15 money lies you should stop telling yourself by age 30

You’ll always be allowed a few life mulligans, but by the time you’ve hit the big 3-0, you should have sorted out most of the reckless habits we tend to fall into as young 20-somethings.

This is especially true for money matters, considering you’re close to entering — and need to prepare for — your peak earning years.

While most of us have a general idea of what it takes to succeed, we sometimes let ourselves — and a few money lies — get in the way.

Don’t let these 15 lies hold you back.

Mandi Woodruff contributed to an earlier version of this post.

So long as my job pays well, it's OK if I hate it.

The job market may not be what it used to be, but by age 30 no one should be toiling away at a job that leaves them stressed out and dissatisfied with life. Sometimes your just have to say no, and have the confidence to quit.

We were inspired by a young woman who wrote about turning her back on a lucrative job on Wall Street when years of 14-hour work days made her overweight, burnt out, and miserable.

'I'm a few months into my new job (as an asset manager for a nonprofit) and it's made my life richer. I'm making an effort to breathe, smile, eat healthier and have positive thoughts about my future,' she wrote.

'I took a pay cut of about 30% to change positions, but I don't think that I should be applauded for making the choice to accept less pay -- I don't view it as a sacrifice.'

If I turn a blind eye, somehow my finances will figure themselves out.

The worst things to do in your early 20s is to ignore financial red flags when they arise.

Check your bank account, no matter how fearful you are of how low the number might be; don't leave your credit report untouched; and take advantage of work benefits, such as the 401(k) match.

If you're broke, you might as well know it and own it. It's the only way you'll ever truly be able to do something about it.

Banks and bill collectors will get their way no matter what I do.

At some time (and for a lot of you, many times), life eventually will get in the way and you'll find yourself on the wrong side of your bank or, worse, a bill collector.

Stand your ground. Negotiating your way to lower credit rates, car insurance, cable bills, and bank fees is possible, especially if you monitor your accounts dutifully and refuse to take no for an answer.

If you're ever in doubt, think about Kenny Golde, a 40-something Hollywood producer who managed to negotiate $US220,000 worth of debt down to $US70,000.

I should buy a home because that's what grown-ups do.

Don't make the big move until you're fully prepared financially.

Real estate expert Scott Sheldon points out that consumers aren't ready for homeownership until their debt-to-income ratio falls below 45%:

Calculate your DTI: Proposed mortgage payment + all minimum monthly debt obligations ÷ gross monthly income.

Calculate your maximum mortgage payment: Gross monthly income × .45 (45 per cent DTI) − all minimum monthly debt obligations.

If you're not quite secure financially, but want to move into a house, consider roommates, Egan suggests, especially if you're not married yet: 'If you're single, have some roommates to help ease the burden of the mortgage so it doesn't affect your other savings for retirement or other goals.'

If I start dipping into my savings now, I'll have plenty of time to make up for it later.

If you've managed to build a 401(k) with your employer, now is not the time to start chipping away at all that hard-earned retirement cash.

For starters, you'll be charged a hefty fee for early withdrawal. It's also tantamount to stealing from yourself in old age.

When times are tight, trim your spending, reevaluate the purchase you intend to make, or find ways to supplement your income. You'll thank yourself later on when you see how much your savings grow.

I'm too inexperienced to start investing.

You don't have to be an expert about personal finance or use fancy economic jargon to start investing. You don't have to come from an affluent family, and you don't even have to earn a massive paycheck.

In fact, it's pretty simple with the right resources, and it can pay huge dividends in the long run.

Ramit Sethi, author of 'I Will Teach You to Be Rich,' did the maths: If you put aside just $US10 per week, after five years (assuming an average 8% return), you would have $US3,295, and after 10 years, you would have $US8,136. Putting away $US50 a week would result in $US16,473 after five years and $US40,678 after 10 years.

Imagine how much money would accumulate if you set aside a bit more each week, and did that for several years.

I'm a failure because I'm not getting paid as much as other people my age.

There's a reason older people are nostalgic for their 20s. They have got a mortgage and a brood of screaming toddlers and they miss doing whatever they pleased whenever they pleased.

Perhaps they have forgotten the first few years out of college -- that frenzied time when everyone was out for themselves, scratching, clawing their way to success?

There's such thing as healthy competition, but spending every waking moment trying to 'beat' your peers is a quick way to wind up alone and miserable. Do yourself a favour and focus on your own path, not stalking your friends' career moves on Facebook and LinkedIn.

I can still afford to eat like I'm 16.

No one can predict the future, but chances are yours involves a body that has far less tolerance for chilli cheese fries and 4 a.m. taco runs.

Research shows that as you age, your muscle mass decreases and your fat increases, which ultimately decreases the number of calories your body burns, meaning you don't need to eat as much.

Do your finances -- and your belly -- a favour and change some of your eating habits now.

You don't need to whip up five-course meals every day of the week. Niche grocery stores like Trader Joe's and Whole Foods post simple recipes on their websites to match their inventory, and there are even businesses that will send healthy 'meals-in-a-box' straight to your home.

I can still pull off the outfits I wore in college.

There's a saying career experts love to toss around: Dress for the job you want, not the job you have.

It makes sense. Unless you've managed to finagle your way into your dream job by age 30, part of the battle is making others believe you can handle it.

Leave the flip-flops at home, invest in a wardrobe that shows them you're ready for responsibility -- and the heftier salary that comes with it -- and you're already on your way.

If I get approved for new credit, obviously I can handle it.

There may come a time when your credit limit doubles, triples, or even quadruples, especially if you've spent a few years dutifully paying down each of your debts.

If your limit increases, you've probably earned it, but don't bite off more than you can chew, and be wary of lifestyle inflation. No matter how big your credit limit, or how fat a mortgage loan your bank offers you for a new home, that doesn't mean you have to take it.

Know your limits and what you can afford. Then tell them how much you need.

I'll save a bunch of money by buying the cheapest option.

Some things are worth buying secondhand, but not everything.

It's tempting to try to 'save money' by buying inexpensive, low quality things, but oftentimes those cheap products will cost you in the long run.

Learn to invest in things that have value. They don't have to be big purchases, either; there are several everyday items that can pay for themselves, and you'll want to be careful of skimping on things like mattresses, computers, and more.

Everything will be work itself out eventually, so I can do whatever I want right now.

While optimism is a good quality to have, too much optimism can be dangerous, especially when it comes to money.

People tend to assume they will be making significantly more money in their 40s, explains certified financial planner Michael Egan, which they use to justify overspending in the present moment.

'The rule of thumb should be to live below your means,' emphasises Egan. 'Savings first should be your mentality: Save for retirement first, and spend with whatever is left over. What people typically do is the opposite of that, thinking, 'I've got to buy this, this, and this, and whatever's left, I'll save.' Pay your future first, and make sure your present is secure.'

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