These common mistakes can derail your retirement plans. Here's how to avoid them. By David Muhlbaum, Senior Online Editor September 3, 2014 You want to retire someday, right? That's supposed to be the payoff for putting in all those years at work. But these days, with corporate pensions disappearing and lifespans on the rise, comfortable golden years are looking more and more elusive. See Also: SLIDE SHOW: 10 Best College Towns to Retire To There are a bunch of reasons you might have to keep working until you can't, rather than stopping when you want to. Here are three big ones: Number one: You aren't letting your company help you save. Many employers will match a certain amount of your savings in the company retirement plan. Amazingly, a considerable number of people pass up this free lunch, either because they don’t contribute enough to earn the match or they don’t contribute at all. Number two: You're using your nest egg as a piggy bank. While you can take a loan from a company retirement plan, it can be costly. And the worst problem of all is if you end up never paying the money back -- not only will your nest egg suffer, but you'll have to pay taxes and early-withdrawal penalties on the distribution. Advertisement Number three: You haven't thought through your Social Security benefits. Many people take the money and run once they become eligible at 62, only to discover that it's not enough to live on. Remember that the closer you get to age 70, the bigger your monthly benefit check will be, so it can pay to delay claiming. At Kiplinger.com, we have additional reasons you'll never retire -- seven of them, in fact. Read them and learn to defy the odds. After all, we do really want you to have a comfortable retirement.