40 Career Mistakes No One Over 40 Should Make

1 | Pursuing full-time higher education

"If you want to go back to school, do not go back for a JD, PhD, or MD unless you're extremely passionate about pursuing those options," says Nick Kamboj, the CEO of Aston & James, LLC. "These programs are usually full-time, and will cost hundreds of thousands of dollars." Losing a reliable salary and committing to a prohibitively expensive venture? Yeah, you do the math.

Instead, Kamboj suggests pursuing an MBA. Even top-ranked programs allow students to take courses at nights, on weekends, or even online, so you can maintain your career and level-up your résumé at the same time.

2 | Keeping your nose on the grindstone

You don't need us to tell you that burnout is bad. But in addition to all the obvious side effects—stress, anxiety, depression, sleep deprivation—recent research suggests that regularly clocking 60-hour weeks can physically transform the structure of your brain. Suffer too much burnout, and you'll find yourself with less energy, less creativity, and less motivation to get things done. There's no quicker way to condemn yourself to a career rut.

Thankfully, reigniting the fire under your feet is no tall order. Start by taking off one Friday per month. Then turn off your mobile notifications (that "urgent" email will still be there after lunch). Take a vacation. Meditate. Remember: Your life belongs to you, not your work.

3 | Hiring the wrong people

Once you pass 40, you may find yourself in the position of hiring subordinates. People's lives (and the company's workflow) are now in your hands. No pressure! But if you extend an offer to the first remotely qualified candidate in the hopes of ending the process as quick as possible, it's a huge mistake.

The smartest hiring managers would rather let a position go unfilled than give the gig to anyone who's less than perfect. Scrape the bottom of your referral pool. Post on every job board on the internet. Meet with 100 candidates. Remember: This new person will be on your team for a long time—and you're hiring them to make your life easier. Best to get it right from the start.

4 | Leaving vacation days on the table

According to the U.S. Travel Association, as astonishing 52 percent of Americans don't use all of their vacation days. Don't be part of the 52 percent. Everyone needs to recharge. Or did you already forget the memo on burnout?

5 | Complaining about millennials

"Aside from the fact that most people born in the 1980s and '90s bristle at the term, it's also a mechanism to isolate yourself with your peers and seniors," says Sharon Lipovsky, an executive coach and the founder of Point Road Studios. "Instead of complaining about the new ways things are done or pining for the 'good old days,' embrace curiosity. Learn something new. Try something that makes you really nervous. This mindset will keep you growing in your career—and as a human being."

6 | Labeling yourself as inexperienced

"Changing lanes is pretty common, but a lot of people over 40 feel that jumping into a new career or launching their own business means they are back at square one," says Lipovsky. Newsflash: That couldn't be further from the truth.

Anything you've done in your past is experience for your future. If you're a consultant-turned-interior-designer, your client management skills give you a competitive edge. If you're a banker-turned-lawyer, your experience navigating legal waters sets you apart. Identify any versatile experience you've gained and use it to your advantage.

7 | Barely clearing the bar

If your boss wants 10 ideas by Friday, turn in 20 on Thursday. What goes around comes around—especially in the corporate world. Going the extra mile, and making your boss's day, is the best way to ensure good things come around to you. This advice applies to everyone, regardless of his or her age.

8 | Starting a new business

At a career crossroads—whether you're at a dead end or just plain bored—it's natural to feel an urge to strike out on your own. But "it's likely the worst mistake you can make," says Kamboj. "As many entrepreneurs will tell you, starting and growing a business is 100 times harder than simply looking for another like position."

If you have an irrepressible passion for the business you want to start (and a sizable safety net), go for it. But if you're starting a business just to start a business, look for other work.

9 | Quitting without a fallback

It might have been fine—romantic, even—to up and quit a frustrating, boring job in your 20s. But once you pass 40, it's one of the worst moves you can make. "In the heat of the moment, it's easy to forget about things like your health insurance, your mortgage, or your 401k," says Beth Tucker, CEO of KNF&T Staffing Resources. "If you have something else lined up, even if it's a contract role, you'll be in a better position to continue to pay for important items like these—and keep your way of life relatively uninterrupted."

10 | Shopping around a splashy résumé

Here's a good rule of thumb for résumé writing: There should be one page (at most) for every decade of experience. In other words, yours shouldn't be longer than two pages, max. Also, stick to the facts. No need to adorn it with fancy fonts or splashy graphic design tricks. And leave off your headshot. If a hiring manager wants to see what you look like, they'll find you on LinkedIn. (Your page is up-to-date, right?)

11 | Flopping in interviews

By the time you hit 40, you should really know how to nail a job interview. Saying the right things is, of course, key. But not saying the wrong things is equally important—if not more so. Don't trash a former employer. Don't dangle a competing offer. And don't answer the "weaknesses" question with a, well, weak answer (i.e., "My only weakness is that I have no weaknesses.").

12 | Letting your old skills get rusty

A soldier is only as good as his arsenal. Same goes for corporate drones. If you let any hard-earned skills—speech-giving, a coding language, mastery of PowerPoint or Excel—languish, you're only setting yourself up for failure. To keep your skills sharp, be sure to, every so often, jump back in the fray and do some hands-on work.

13 | Neglecting to learn new skills

Refusing to adapt—namely, by picking up new skills—only guarantees one thing: You'll get left behind. "You can also stay apprised or learn a new language set by simply reading periodicals that are well-known within the industry of interest," says Kamboj. "By simply knowing the vernacular or lexicon of a field, you're already perceived to be educated and trainable—and, hence, more employable." Keep your knowledge sharp.

14 | Expecting a major change to be lateral

It's not impossible to switch fields after 40. But, instead of just, well, doing it, it's best to do what Kamboj calls the "two-step jump." Here's how it works:

Let's say you're senior in one industry. When you pivot to a new industry, you'll have to first take on a role that might have a lower salary or fewer serious responsibilities than what you're used to. Quickly, however, you'll develop foundational skills—and that's where the "two-step jump" comes in. Instead of gunning for a promotion, you're better off seeking a newer, shinier role at a newer, shinier company. With your newly won skills, plus decades of career experience, you'll land a gig in no time. From start to end, the process takes only a year or two.

15 | Staying in one lane

Yes, you have designated duties. And instinct says to punch in, do you job, and punch out. But in this age of corporate consolidation, that's a frankly stupid move; in a merger, the first people to go are the rank-and-file old guard. So figure out ways to make yourself valuable to people across your entire company. Take on assignments from other teams, learn a new essential skill, help on-board new hires—whatever you need to do to stand out. Don't think of it as extra work. Think of it as job insurance.

16 | Neglecting creative expansion

There's a rule at Google, arguably the country's most innovative company, called the "20 percent rule," meant to dictate how employees should break up their time: 80 percent should be spent on assigned duties, while the remaining 20 percent should be spent on pursuing any work-related creative endeavors. (It's effective for both employee morale and company assets: The 20 percent rule resulted in Gmail and Google Maps.)

Now, we're not saying you should spend a whole fifth of your day on, well, not doing your directed job. But if you can find a portion of your time to creative pursuits, everyone wins.

17 | Dressing down

You've heard it a million times: "Dress for the job you want, not the job you have." Sure, yeah—how about dressing for the job you have, too? By 40, if you've stuck on the same career path and ascended at a normal rate, you're likely at a fairly plum perch. Dress like it.

18 | Fumbling the raise question

Everyone wants more money. But few people know how to effectively get more. Instead of walking into your boss's office and saying, "Hi, I would like more money," go in with a battle plan. Come with an exact figure (6 percent, or three times the standard cost-of-living bump, is a good starting point). Offer to take on more responsibilities. Time your conversation when your boss is in a good mood. And never, ever—under any circumstances—threaten to leave if you don't get what you want. If you're denied, bide your time, and circle back in a few months.

19 | Losing your cool

The higher up the career ladder you climb, the more stressful things get. But flying off the handle is never okay. Such behavior worries the higher-ups and frightens the direct-reports. If a someone pushes you to the point of fury, don't rashly engage. Take a deep breath, cool off, and revisit the matter with a level head.

20 | Sticking with a soul-sucking job

Once you hit 40, it's a good bet you have some good momentum in your career (and some plush perks, too). "This can paint a future that seems rosy and compelling, but if you really are drained by and just plain don't like what you are doing, there are plenty of other paths," says Lipovsky. "You've just got to get clear on what you want and go after it. Don't give in to the proverbial golden handcuffs."

21 | Constantly multitasking

The ability to juggle tasks is no doubt a good one. But if you're constantly tossing balls in the air, you're doing yourself approximately zero favors. As one study out of Stanford University revealed, people who frequently multitask are more likely to get derailed from important tasks (and also suffer reduced working memory, which, sorry, already declines with age). The solution: pick a task, see it through, then tackle the next.

22 | Eating sad desk lunches

According to research published in Organizational Dynamics, eating lunch at your desk won't save you any time during the day. In fact, it has the opposite effect. By actually stepping out to grab a bite, you'll find your productivity boosted and your energy levels recharged. Finally, a solution to the dreaded afternoon slump!

23 | Refusing to delegate

It's natural to hoard your work. But the best employees—those of the corner office caliber—have mastered the art of delegation. Your coworkers are there to help, especially if they're below you on the food chain. Don't neglect that. Once you can let go of any neurotic tendencies about how, exactly, you like things done, you'll be able to accomplish a lot more during your day.

24 | Delegating everything

Still, there should be some stuff on your plate. After all, it's not called "work" for no reason.

25 | Getting stuck in your "story"

Growing your career is what Lipovsky calls a "visionary act." The thing to keep in mind, however, is that not all visions are about the future. To ensure yours is on the right track, you have to double-check your "story," and make sure yours isn't getting in your way. Huh?

"For example, maybe you've been carrying with you a story that you're a really hard worker," says Lipovsky. "That story has probably worked for you in a lot of ways. You've worked hard and you've gotten good results. But if you want more balance and fewer hamster-wheel feelings, you need to rethink your old story."

Instead of holding fast to an unshakable work ethic—showing up first, leaving last, and piling through everything on your desk like a steamroller, day in and day out—maybe try taking a few breaks. If it doesn't work out, and you still feel like you're on a grind, no sweat: just go back to the way things were.

26 | Taking jobs just for the money

If you haven't figured it out by now, money isn't the key the happiness. Yes, having a cushy salary can get you nice things. But it only goes so far. In fact, according to a recent study out of Princeton University, happiness levels tend to peter out around $75,000-per-year. If you're willing to drop everything for a salary higher than that—and only for the salary—reconsider your priorities.

27 | Sticking with one income stream

Fact is, these days, a single source of income isn't enough. For major boost to your savings—and to set aside enough dough for a rapidly approaching retirement—you'll need to have two or even three gigs going at once. And don't take it from us. Take it from Grant Sabatier, who set aside a cool million before he turned 30, all by taking on a few choice side hustles.

Moonlight as a real estate agent. Operate a ride-share (Lyft or Uber) on your commute. Open up a weekend flea market. Every extra penny counts. And for more money-making ideas, check out these 20 Lucrative Side Hustle Ideas for Putting Your Savings on Steroids.

28 | Succumbing to procrastination

"I'll deal with that later" is pretty much the base state for human nature. But there's an easy way to conquer procrastination once and for all (sending your career to new heights in the process): Swear by the "Two Minute Rule." Coined by David Allen, the author of Getting Things Done: The Art of Stress-Free Productivity, the rule is astonishingly simple. If something comes across your desk, and you can knock it out in 120 seconds or less, do it. If not, deal with it later.

29 | Backstabbing

Maybe you're a total mensch. If so, politely ignore this advice. But if you've deployed dirty tricks—stabbed coworkers in the back, thrown them under the bus, blamed them for your mistakes, that sort of thing—to get where you are, you're doing the whole career thing wrong. Such behavior will only get you so far. To really climb the ranks, prove that you're worthy of ascendance by playing nice with others and regularly going above and beyond your responsibilities.

30 | Spending decades in an office chair

As anyone who suffers from it can tell you, chronic pain is debilitating and distracting. If you've hunched at a desk for eight hours a day, five times a week, for twenty years straight, you're bound to suffer some problems—in your shoulders, in your neck, and especially in your back. Do some course correction immediately and invest in a standing desk. At first, try to stand for four hours each day. Then, four. Getting up and out of your seat is one of the top doctor-recommended methods for conquering spinal pain once and for all.

31 | Sleeping at the office

Whether it's due to long hours or trouble at home, no one—above or below you—wants to see that. We won't tell you to work less than you need to, just as we won't tell you to power through an uncomfortable home environment. We will, however, suggest that you rent yourself a hotel room. And if you'd rather not dish out the dough, well, Heres's the Best Way to Get Your Hotel Room Comped.

32 | Showing up late

Nothing says "I don't care" like a habit of showing up late to meetings or presentations. (For dial-in calls, feel free to have a five-minute leeway...for "technical difficulties.") If you need help sticking to your itinerary, steal these 15 Easy Hacks That Will Make You On Time—All The Time.

33 | Showering with warm water

It sounds silly, but the temperature of your shower can have an effect on your work—at least on a micro level. Instead of showering each morning with warm water, consider turning the temperature down. "Cold water is invigorating, and it also activates brown fat, growth hormones, and androgens to help give you the drive to take on the day," says diet and lifestyle expert Denny Hemingson. The math is simple: more energy means more productivity means better results on the job.

34 | Acting like you're a decade younger

The job market can be frustrating, doubly so for people over 40—and triply so for people over 40 entering a new field. Someone who's 40 or over might be used to a higher salary, something that a spouse or child or elderly parent can also survive on. As such, many entry- and low-level jobs are far more likely to go to a recent college graduate who's willing to work for peanuts. That's why you need to stand out from the crowd.

"Is it your age that's the problem here or your attitude? What are you doing to appear more relevant?" asks Robert Matuson, the founder and president of Matuson Consulting. Now, that doesn't mean you should start hurling around millennial lingo or dressing like a 20-something. But deploy common sense: keep your computer skills fresh, clean your social media accounts, that sort of thing. And remember, you've got something they don't: Experience.

35 | Saying "yes" to everything

Taking on a Hulk-sized workload can endear you to higher-ups. But if you're already a higher-up, you don't need to endear yourself to anyone. Plus, by 40 you hopefully have a good idea on what work you like—and what work you don't. When in doubt, remember: delegate, delegate, delegate.

36 | Saying "no" to everything

No one likes a "yes man." Everyone hates a "no man." Knowing when to say "no" at the right moment is an essential skill. Here's the thing, though: the "right moment" can't be every moment.

37 | Firing people on a whim

Face it: People are going to screw up. It's human nature. Instead of flying off the rails and firing frequent offenders, use screw-up opportunities as teaching moments. You don't want your office to get a gallows reputation.

38 | Wasting time on fruitless projects

Once you hit 40, you should have a good grasp on what work will make waves. (We're talking about the good kind of waves—the kind that bring in bonuses and promotions and corner office assignments.) Spending a week on a project that's going nowhere means you're spending a week going nowhere.

39 | Blowing through budget

If you're lucky enough to have some corporate-sanctioned plastic, do your finance department a favor and stick to allotted expense budget. Yes, passing the limit every so often happens, especially during busy seasons, when frequent travel and high-profile meetings are par for the course. But going overboard every month—or blowing through it by an insane margin—shows carelessness.

40 | Using corporate funds for personal expenses

Hey, look: it's a one-way road to unemployment!

To discover more amazing secrets about living your best life, click here to follow us on Instagram!