Perception might be reality. But that's not necessarily the case for pre-retirees. For Americans on retirement's doorstep, misconceptions are reality.

Yes, many Americans retire thinking and imagining this or that lifestyle, and the reality that awaits them is entirely different, say experts.

So, what are the biggest misconceptions people have about retirement and, more importantly, what can you do to avoid or deal with unrealistic images of your golden years?

The transition from working to retirement is easy. People underestimate how emotionally draining the transition from work to retirement can be, says Mike Branham, a certified financial planner with Cornerstone Wealth Advisors in Edina, Minn. "Retirement is sometimes a panacea that is built up in one's head about being 'free.'"

But, says Branham, few realize how much of their identity is wrapped up in what they do for a living and how difficult it can be to wake up one day and not follow the routine that's become habit over the past 30-plus years. "It takes time to adjust," he says.

Retirement is stress-free. Pre-retirees also think that "retirement is a trip to Nirvana," that the golden years are no big deal, says Marty Kurtz, a certified financial planner and president of The Planning Center in Davenport, Iowa.

"It's a huge deal, one of the biggest deals of our lives," says Kurtz. "It's a change in stature, status, economics, friendships and health. It's the realization that we're approaching the end of our lives and that we must prepare for whatever that brings. It's a time of life when we must embrace the uncertainty of life and live with purpose. We need to share our fears and be resolved that we can make a difference with our time, our money, and our sharing of our life experiences with those we love."

One way to deal with the perception that retirement is anxiety-free: Talk to retirees about how they made the transition and learn from their mistakes.

You'll have plenty of free time. Pre-retirees also underestimate how they'll occupy themselves in retirement, says Branham. They might imagine themselves sitting around the house all day with nothing to do, when in fact they'll have hobbies, volunteer work, and "honey-do" lists to fill their time. "We have clients tell us, post-retirement, that they wonder how they ever found the time to work given how busy they are in their day-to-day retirement," says Branham.

Others have a similar take on this misconception. "Many retirees find that they have substituted work-related stress for lifestyle-related stress," says Tom Potts, a certified financial planner and professor at Baylor University in Waco, Texas. "Beyond financial concerns retirees find that they need to develop more outside interests, they have more health issues, and family relationships have not automatically improved due to retirement."

How to deal with this perception? Consider identifying and prioritizing all things you want to do in retirement and map out how much time you want to spend on those activities and when.

The money's all set. When it comes to the financial part of retirement, Branham says pre-retirees really don't know what "enough" is. Few pre-retirees, he says, have a sense of what their monthly or annual expenses will be, their sources of retirement income, or the size of the nest egg required to sustain their lifestyle.

Potts shares that point of view. "Most pre-retirees don't have a good estimate of what an adequate nest egg should be to provide the lifestyle they desire in retirement," he says.

To be fair, Potts says the current low interest rate economic environment is making it more difficult for retirees to reduce the risk of their portfolios and produce a reasonable income stream from their investments. What's more, tax laws and what not can make estimating income and expenses not only difficult, but confusing.

Some of the confusion, says Branham, can be chalked up to retirement expenses they hadn't fully considered, such as travel, health care and long-term care. But much of it stems, he says, from a "head-down, push-forward approach taken in the later years of their working life when they didn't fully commit to thinking about life after work. "

How to deal with this misconception? Don't wait until the last minute to evaluate whether you're financially ready for retirement, says Branham.

Obsess on your number, not your behavior. As you calculate whether your nest egg is adequate to fund your lifestyle, avoid being overconfident that it will all work out in reality as it does on paper. "One of the biggest misconceptions out there is the overconfidence of thinking we know what we don't know," says Ed Gjertsen II, a certified financial planner with Mack Investment Securities in Northfield, Ill.

Yes, you don't really know, even when using sophisticated software and Monte Carlo simulations, what your portfolio will be worth in 20 years, or how much you'll need to pay for health care expenses over the course of your lifetime. Such software and simulations are "just not very reliable," says Gjertsen.

"I doubt very few planning projections back 15 or 20 years ago factored in near-zero interest rates and an anemic stock market," says Gjersten. "While the S&P 500 may be 40% above the highs of 2000, it was quite a roller coaster ride for 13 of the last 15 years."

What to do? Don't obsess on your number, the value of the nest egg that you think you need for your desired lifestyle. Instead, think about what you can control — your behavior. "The overall success of an individual's retirement plan is more dependent on their individual financial behavior than the overall investment success of the adviser," says Gjersten.

Don't worry about inflation. Nick Nicolette, a certified financial planner with Sterling Financial Group in Sparta, N.J., says pre-retirees also underestimate the effects of inflation on future spending. "It is hard for them to picture their expenses doubling, or even tripling in retirement," he says.

Nicolette's advice: Visualize your lifestyle choices and what your core expenses might look like in two or three life stages — active, slower pace and the sedentary stage. "This allows for a realistic view, in our opinion, and helps them to see why they need to not spend all free cash flow now and reinvest funds for the future," he says.

Take Social Security early. Another misconception has to do with Social Security. Many Americans take Social Security prior to full retirement age because they fear that Congress will severely reduce or eliminate their benefits.

But that's the wrong reason for taking Social Security early. "We don't know what we don't know," says Gjersten. "None of us have an expiration date on the bottom of our feet to determine when we die. Those taking Social Security before full retirement age due to sustainability concerns or worries over an early demise may need to change their perception. The long-term negative financial consequences for early benefits is undeniable."

Talk to a financial planner. Don't think you can do this alone, without some help, guidance, or advice. "A financial planner can help uncover these misconceptions and bring clarity to these areas of confusion and misunderstanding," Potts says. "Pre-retirees should devote some time to think about retirement and what they need to address in a timely manner to feel confident that they are on the right path."

A common mistake, says Potts, is to "assume everything will work out or be so afraid that they are not on the right path that they actually want to remain ignorant concerning the corrective actions needed to produce a successful retirement."

Robert Powell is editor of Retirement Weekly, contributes regularly to USA TODAY, The Wall Street Journal and MarketWatch and teaches at Boston University.