More than half of Americans haven't forgotten the tough lessons of the Great Recession and the stock market implosion, meaning they've been sitting on the sidelines as the market returned to boom days. And that's taking a toll on those saving for retirement.

Fifty-one percent of Americans, according to the latest COUNTRY Financial Security Index survey, still don't trust the market or haven't been able to bring themselves to dip their toes back in. And among those waiting it out, 56 percent say they don't have enough money to invest. Another 12 percent say they don't trust stock and bond markets, while 11 percent say they don't know enough to get started.

Those who are investing — 45 percent — say that they're paying close attention to how their investments are doing, and are concentrating on the future. Most of them — 88 percent — are in the market for what it can do for their long-term savings, while 78 percent make sure that they go over all their investments at least once a quarter.