One of the biggest retirement mistakes you can make is not realizing what you don't know.
I regularly hear from people in or near retirement who misunderstand how Social Security works, dramatically underestimate life expectancies or fail to plan for big expenses, such as long-term care or taxes.
These are not folks looking for advice.
They have already made up their minds and want to argue about financial-planning precepts, such as when to take Social Security or how much retirement is likely to cost.
But what they think they know just isn't so.
The reality is that most people don't get good, objective financial advice before they retire, said actuary Steve Vernon, consulting research scholar at the Stanford Center on Longevity.
Many people simply wing it, figuring that if they have a Social Security check and a little savings, somehow everything will work out.
Unfortunately, retirement is complicated, and your decisions can have irreversible consequences.