Trying to plan for something that is decades away can seem nearly impossible. That's why when you're just starting out, retirement planning mostly involves just saving as much as you can. Only as retirement gets closer can you begin to have a clearer idea of what your life will look like once you stop working.

While everyone has different needs and lifestyles, there are some common misconceptions about planning for and living in retirement. Here are three aspects you may need to rethink.

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1. Thinking you can't save in a retirement account

Tax-advantaged accounts such as IRAs and 401(k)s exist to help you save for retirement by allowing your money to grow tax-deferred. If you're not utilizing them, then you're missing out on tax benefits that can help you save for a secure retirement. 

First, if your company offers a retirement plan, consider signing up and having money automatically deducted from your paycheck. And if your company offers a match, make sure you're contributing enough to earn it.

But even if you don't have access to an employer-sponsored retirement account, there's still a way for you to save in a similar tax-sheltered account. In fact, anyone with earned income can open and fund an IRA. For 2017, you can contribute $5,500, and if you are aged 50 or older, you can contribute an additional $1,000.

2. Thinking you will spend less in retirement

You may be saving to replace 70%-80% of your pre-retirement income, but you may need to replace 100% of your income. Lifestyle preferences can have a big impact on how much money you need during your retirement. While some people plan on downsizing and moving to a less expensive area, if you plan to stay where you are and keep your current lifestyle, it's possible your living costs will remain the same in retirement as they are leading up to retirement.

While some of your bills may go away, like budgeting for work attire or commuting costs, you may start spending more money on other things, such as more frequent travel. And eventually, your healthcare costs may rise.

As you get closer to retirement, try to think realistically about how you will spend your time once you are no longer working. Then consider your current monthly income and expenses and how those will change -- and you may be surprised to realize that the rule of thumb that says you'll spend only 70% of your pre-retirement income in retirement may not be accurate.

3. Thinking Social Security will be enough

If you're like many people, you may be relying too heavily on Social Security benefits to support your retirement needs. According to the Social Security Administration, among the elderly, 48% of married couples and 71% of singles count on Social Security benefits to provide 50% or more of their income. And yet a January 2017 report shows that the average Social Security monthly benefit was $1,248.67.

Social Security was never meant to be your only source of retirement income, nor was it meant to be your largest provider of income during your retirement years. That's why it remains a top priority for individuals to begin saving and building their own retirement funds to provide the bulk of their income when they retire.  

No one ever said planning for retirement was going to be easy, but it helps to know the facts and to understand all of the different aspects and pieces of the retirement puzzle so you can make informed decisions as you plan and prepare for your own retirement.