When it comes to retirement, there's so much advice out there that it can be hard to make sense of it all. Whether you get your information from the internet, your financial advisor, or your Uncle Bob, some of it will be accurate, while some will steer you in the wrong direction.

While there's no one way to plan for retirement, there are a lot of ways not to plan for retirement. And if you follow bad advice, it can end up costing you thousands (if not hundreds of thousands) of dollars by the time you retire. With this in mind, here are four retirement myths you can't afford to believe.

Senior couple enjoying retirement walking on the beach

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1. Your monthly expenses will decrease when you retire.

While it's true that some expenses will decrease -- you may no longer have to financially support your children, you may downsize to a smaller home, and you can save money by avoiding your daily commute to work, for example -- other expenses will increase.

As you're planning for retirement, envision what your lifestyle will look like. Are you planning on spending your time playing with the grandkids or catching up on your reading? Then you may not need to save quite as much. But if you want to travel the world or pick up an expensive hobby, you may end up spending more than you expected.

It's also important to build a buffer into your savings to cover emergencies. Nobody likes to think about health problems, but they happen with greater frequency as you age. These expenses add up quickly, so be sure you're not just saving for the fun stuff.

2. You don't earn enough to save for retirement.

Without a doubt, it's hard to save for retirement. No matter how much you earn, there are always bills to pay and mouths to feed, which take priority over retirement. But no matter how much (or little) you earn -- even if you're earning the minimum wage -- you can still take baby steps.

First, start by writing down your goals and creating a budget. People who have a written retirement plan are 60% more likely to increase their retirement fund contributions, so break out the pen and paper.

Every extra dollar counts, because with the power of compound interest, your savings will grow more the earlier you start saving. So, for example, if you invest just $5 per week in an account that earns an annual return of 7%, after a year you'll have saved roughly $269. After five years, that turns into over $1,500. Not bad for saving what amounts to the cost of a cup of latte each week.

This is also why it's important to start saving as early as possible. Many people put it off until later, thinking it will get easier to save as you get older and (hopefully) start earning more money. But it's always difficult to save at any age, and putting it off only diminishes the salutary impact of compounding returns.

3. You can rely on Social Security.

While Social Security is not going anywhere anytime soon, it is struggling. According to the Social Security Board of Trustees, the program will be facing a cash shortage within the next 20 years.

Because Social Security is funded by taxpayers, there will always be cash coming into the program. But with more people retiring than funding the program, retirees may see their benefits slashed in the future.

To be clear, you will still receive Social Security benefits during retirement, but they may not be as much as you're expecting. This is good news for people who are worried that Social Security is crumbling and they'll lose all their benefits. But it's bad news for those who are relying on those benefits to cover their everyday needs during retirement.

The only way to prepare is to simply save what you can. If you prepare for the worst and assume you'll receive very little in Social Security payments, you'll be ready in case benefits are cut. And if you receive more in benefits than you expected, it will just be a pleasant surprise.

4. You need at least $1 million to retire.

Putting an exact number on how much you need in order to retire makes the planning process sound easier than it actually is. And while you may come across well-intentioned advice saying that you need to save $500,000, $1 million, or X amount of money for retirement, everyone's situation is different and blanket statements like these are prone to be inaccurate.

How much you'll need during retirement depends on a wide variety of factors, such as where you live, what your retirement lifestyle looks like, and what types of health issues you may face as you age. So while one person may be able to comfortably retire with $500,000 or less, others may need at least $1 million just to make ends meet.

Retirement requires a lot of planning and saving, and it's smart to do research to help you along the way. But retirement myths can hurt your progress and cost you a lot of money down the road. By separating fact from fiction, though, you'll be closer to reaching your retirement goals.

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