John has been investing for about five years—long enough to know that a bull market is a market in which stock prices are climbing strongly and a bear market is one in which they're languishing. The only trouble is, he's never quite sure whether he's got the bull by the horns or is about to be mauled by the bear. With his life savings riding on the answer, he says that he approaches each day with nail-biting nervousness.

"Every time the market climbs, I'm wondering whether I should sell to lock in my profits. When it drops, I wonder whether I should sell to cut my losses," he says. "Most of the time, I don't actually do anything—other than worry about it."

Anecdotal evidence indicates that John, a broker who asked not to be named for fear of losing all his clients, isn't alone. Investing makes many people nervous, because they know that their future financial health can hinge on the choices they make. And there are a huge variety of highly complicated options confronting investors every day.

However, investing doesn't have to be difficult or nerve-racking. In fact, wise investing is simple, once you understand a few key facts.

First and foremost is this: The goal of this game is not to accumulate more money than God. It is not about getting a 50 percent or 40 percent or even 20 percent investment return. It is not about bragging at cocktail parties. It is this and only this: having the amount of money you need when you need it.

Make this your mantra. If ...

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