As kids, America's richest entrepreneurs dreamt of curing patients, flying jets, writing plays and bagging base hits for the Chicago Cubs. Instead, they started hundreds of companies, employed hundreds of thousands of people and bagged $1.06 trillion.

In the accompanying slide shows, 21 self-made members of the 2007 Forbes 400 list offer an exclusive, introspective and often playful peek into their best days, worst qualities and hardest lessons.

We also coaxed them into sharing their thoughts on how to invest $100,000 right now (a few said put it with them); luck's contribution to their success (95 per cent, says Kenny Troutt, founder of Excel Communications); and the pitfalls of leaving too much to the kids (money man Richard Rainwater says $50 million is too much, while $1 billion each works for supermarket and oil titan John Catsimatidis).

They even told us with whom they would most want to share a cocktail--two said "me."

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Sure, there was some ducking and weaving. When asked for the next billion-dollar idea waiting to be exploited, Donald Trump replied, "If I knew, I wouldn't tell." Logging tycoon Tim Blixeth's answer: "Stay tuned to 2008!"

One message came through loud and clear, though: It's good to be the guy in charge--and the money's nice too.

The top eight spots on the Forbes 400 belong to entrepreneurs, as opposed to well-paid corporate soldiers or the silver-spoon set. The combined net worth of the top eight hit $237 billion, or 15 per cent of the whole pie. And of the entire list, 270 (or 68 per cent) are self-made, up from 261 last year. Average net worth of all self-made members: $3.9 billion.

While their conquests run the gamut, from real estate and oil to media and technology, these billionaire-entrepreneurs also have a few things in common, according to our 20-question survey.

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A healthy chunk admitted that they are impatient to a fault. (Patience might be a virtue, but it might not make you rich.) As for guilty pleasures, food was especially delicious--Sandy Weill, former head of Citigroup, goes for chocolate sorbet and pizza with jalape�os.

Then again, who's got time for guilt when you're worth $2.4 billion? Says media mogul Mort Zuckerman: "There used to be guilt associated with most of my pleasures, and now there is none."

When it came to best days in life thus far, weddings and births took the cake--with one glaring exception. Casino kingpin Phillip Ruffin's best day ever: Aug. 10, 2007, when he says he put "$1.24 billion into my checking account."

Other answers were all over the map. Favorite books ranged from, yes, War and Peace to The Black Stallion; some even cited books they themselves had written. The group's study-to-party ratio in college bounced around too--not least because a few didn't go to college.

Great wealth doesn't come without a few bruises, and the group was fairly forthcoming--even poignant--when it came to sharing hard lessons learned. Manufacturing titan Michael Heisley had to admit that "wealth is one of the most corrupting influences in my life." Kenny Trout's epiphany: "Money does not buy happiness."

Of all the respondents, though, 86-year-old James Sorenson, the largest shareholder in Abbott Laboratories and a junk-food enthusiast, perhaps best captured the fundamental spirit of entrepreneurship. Asked for the hardest lesson he had to learn, he replied: "To spend my energy and resources investing in my own ideas, rather than those of other people. I need to drive my own vision."

And that's why he's worth $4.5 billion.

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