"Retirement is like a long vacation in Las Vegas. The goal is to enjoy it the fullest, but not so fully that you run out of money."
-- Jonathan Clements

The quip above is amusing, but it also points out a critical aspect of retirement: the need to have our retirement dollars last for the rest of our life. Succeeding at that goal isn't likely to happen by accident, so it's worth learning more about retirement and investing for retirement, in order to have the best shot at a comfortable future.

Surprised grey-haired man with hands on his cheeks

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Here are 20 eye-opening facts related to retirement. See which ones surprise you the most.

You might live a very long life

63: If you imagine that most people work until about age 65 or longer, you'd be wrong: The average retirement age was recently 63. 

72,000: Meanwhile, Americans are living longer than they used to. It's estimated that America is home to about 72,000 centenarians (people aged 100 or older).

38: Some retirees will need their nest eggs to last a whopping 38 years, which is longer than many people work over the course of their lifetimes. If you live to 100 and retire at age 62, for example, you're looking at 38 years of retirement.

28: If you only live to 90, that's still a significant 28 years that your dollars will need to last. According to the Social Security Administration, "About one out of every four 65-year-olds today will live past age 90, and one out of 10 will live past age 95."

70: Because of the possibility of living a long life, personal finance guru Suze Orman has advised that most people should aim to retire no earlier than age 70: "Every dollar you don't spend in your 60s is a dollar that can keep growing for your 70s and beyond." (For some people, this advice is sound. If you have planned well, though, and have socked away enough money for retirement, you could retire much earlier.)

Cartoon-like illustration of a woman looking shocked with hands on her cheeks, next to the word "Wow!"

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Retirement will deliver some surprises

46%: You might end up retiring earlier than you planned to. According to the 2016 Retirement Confidence Survey, 46% of retirees left the workforce earlier than planned, with 55% citing health problems or a disability as the reason and 24% citing changes at work such as a downsizing or workplace closure.

$275,000: Healthcare can cost much more than you think it will. According to Fidelity Investments, a 65-year-old couple retiring today will spend, on average, a total of $275,000 out of pocket on healthcare.

10%: If you're late enrolling for Medicare, it can cost you. Your part B premiums (which cover medical services, but not hospital services) can rise by 10% for each year that you were eligible for Medicare but didn't enroll. The no-penalty enrollment period for most people is any time within the three months leading up to your 65th birthday, during the month of your birthday, or within the three months that follow.

10%: A 2014 MassMutual survey found that 10% of retirees were surprised to find themselves lonely, bored, with a lost sense of purpose, and/or depressed in retirement.

72%: That same survey found that 72% of retired respondents reported feeling quite happy or extremely happy in retirement.

Woman looking surprised, peering at camera as she takes off her glasses

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Most people are underprepared for retirement

Less than $1,000: According to the 2016 Retirement Confidence Survey, about 26% of respondents said they had less than $1,000 saved for retirement (not including pension or home values). A whopping 64% had saved less than $50,000. Here's the breakdown:

Amount Saved for Retirement*

Percentage of Respondents

Less than $1,000

26%

$1,000 to $9,999

16%

$10,000 to $24,999

12%

$25,000 to $49,999

10%

$50,000 to $99,999

10%

$100,000 to $249,999

12%

$250,000 or more

14%

Data source: 2016 Retirement Confidence Survey.

$100,000: According to Fidelity Investments, which administers retirement accounts for many millions of Americans, the average 401(k) balance as of mid-2017 was $97,700, while the average IRA account balance climbed into six figures at $100,200.

21%: Fidelity also reported that fully a fifth of workers don't seem to be contributing enough to their 401(k) accounts to get all the matching funds offered by their employer. That's a shame, since matching funds are free money.

25% to 30%: Anemic retirement accounts are very worrisome, as those accounts are vital for many retirements. Indeed, income from 401(k) accounts has been estimated to represent about 25% to 30% of overall retirement income.

4%: The "4% rule" can help you plan for retirement. It suggests that your money might last about 30 years if you withdraw just 4% in the first year and adjust for inflation in subsequent years. The rule has some significant flaws, but it's still helpful as a rough guide. The table below, showing the initial-year withdrawals that come with various nest eggs, per the 4% rule, can help you see how insufficient even $250,000 in retirement savings might be: 

Nest Egg

4% First-Year Withdrawal

$250,000

$10,000

$300,000

$12,000

$400,000

$16,000

$500,000

$20,000

$600,000

$24,000

$750,000

$30,000

$1 million

$40,000

Data source: Author calculations.

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Image source: Getty Images.

Many people underestimate Social Security

90%: According to the Social Security Administration, most elderly beneficiaries get 50% or more of their income from Social Security, while 21% of married beneficiaries and 43% of unmarried ones get fully 90% or more of their income from it. And that's despite people not receiving huge sums from Social Security.

$1,371: The average monthly retirement benefit was recently $1,371, amounting to $16,452 per year.

$2,687: The overall maximum monthly Social Security benefit for those retiring at their full retirement age in 2017 is still just $2,687, or roughly $32,000 for the whole year.

$3,538: Those who retire at age 70 in 2017 can collect monthly checks as large as $3,538, for $42,456 per year.

2%: Benefits are increased over time to keep up with inflation, with the most recent increase (2%) announced in October to take effect in 2018.

Don't leave your retirement to chance -- and don't let any of these statistics depress you. Plan and save effectively for retirement, and read up on helpful strategies, too. For example, there are lots of ways to boost your Social Security benefits. Simply delaying starting to collect them can beef them up by 24%.