Retirement begins in your 20s or 30s—or, better yet, at birth. That's when you should start investing to build a big enough nest egg so that you can live off income and capital gains from stocks and bonds, rather than off the sweat of your brow and your brain.

My biggest mistake in 25 years of writing newspaper and magazine articles about the stock market started innocently. My intention, in a February 23, 2003, column for the Washington Post, was to show readers how to analyze a stock and decide whether to buy it.

Wharton Business School Professor Dr. Jeremy Siegel is recognized as one of the world's most important scholars on stock ownership and investing. His influential 1994 book, Stocks for the Long Run, became an instant classic.

The task seems incredible. The nation adds 1.3 million to 1.6 million new households a year, requiring a trillion in new financing annually. The rates for owning a home are higher than ever. How is America doing it? Well, it's not by accident, but by design--the Great American Mortgage

Throughout our history, children have lived better than their parents, usually by a wide margin. The math is simple. The U.S. economy, despite occasional dips, has grown consistently at 3 percent a year or more. So, at age 48, you will be four times richer than the average American when you were born.

Then Philip A. Fisher died on March 11, 2004, at the age of 96, it suddenly struck me that being a wise and patient stock market guru may be the best route to a long life.

Heard the one about the monkey and the typewriter? "If one puts an infinite number of monkeys in front of (strongly built) typewriters and lets them clap away, there is a certainty that one of them [will] come out with an exact version of the 'Iliad,'" writes author and mathematical trader Nassim Nicholas Taleb in a recent book, Fooled by Randomness.

If someone steals your car or burgles your house, the normal course of action is to call the police and then sit back while they handle case. But if someone steals your identity, it's an entirely different matter.