Back when he was an oil drill worker in the 1950s, T. Boone Pickens earned just $5,000 annually. Fast-forward about eight IPOs and 15 corporate raids and takeovers later, and the 85-year-old is now worth about $950 million-down from $4 billion before the market collapsed in 2008 and losses in wind-energy investments. But he's not pinching pennies yet: 'I'm back trying to make another billion,' he tells us. Here's how he did it the first time around. -Jen Wieczner

1. At the age of 10 in Oklahoma, agrees to mow his grandma's lawns but grossly underestimates their size. 'It was a very bad deal,' he says,'but she made me stick with it.'

2. Starts delivering newspapers to 28 homes; acquires more routes and reaches 156 houses. 'From that point forward, I always had money in my pocket.'

3. Roughnecks on oil rigs (like on right), at age 16. Loses his $25-per-month college basketball scholarship but tutors for $1 an hour (for a C grade) up to $3 (for an A).

4. Works for Phillips Petroleum on wildcat wells but then resigns just a few years later to strike out on his own.

5. Spends $2,500 in 1956 to start what becomes Mesa Petroleum (named after Texas area above). But blows two years, and $2 million, on a dry well. 'Every loss is a learning experience.'

6. Takes Mesa Petroleum public in 1964, then later merges with Hugoton Production Co., which is 20 times bigger. Runs the ship, but his stake sinks from 23% to 1.5%. 'For 20 years, I had no investment other than in the company,' he says. 'I bet on myself.'

7. Starts acquisition spree, multiplying his company's revenues 15-fold, to nearly $200 million in four years, and discovers oil jackpot in the North Sea (above). Withdraws from Mesa, with his $78 million net worth, and founds energy-focused hedge fund BP Capital Management in 1997.

8. Starts donating $1 billion, with some money going to universities (right) and hospitals. Sees wealth peak at about $4 billion in 2007.

9. Loses half of his net worth during the financial crisis- leaving him around $1 billion then. 'I always feel like if I made a billion, I'll make two, three, five, whatever.'

10. To the surprise of some, he becomes a poster boy for alternative energy, championing wind farms over old-fashioned oil. Now argues wind power only works if natural-gas costs soar. Otherwise, he adds, 'it puts you out of business.'