In 1988, William Post won $16.2 million in the Pennsylvania lottery.

A year later, he was $1 million in debt.

First, he splurged: houses, cars, a plane. Then a former girlfriend sued him for a third of his winnings. His brother was arrested and convicted for hiring a hitman to kill Post and his then-wife in hopes that he'd inherit a share. And after sinking money into a failing family business, Post spent time in jail for firing a gun over the head of a bill collector.

In the end, Post said he was happier living quietly on $450 a month and food stamps than he was when he was rich.

Post's story is an extreme example of the bad decisions and bad luck that leave so many lotto winners wishing they'd never won at all. But while you're more likely to be struck by lightning than hit the winning numbers, an inheritance, a promotion, a legal settlement, selling a business, and reaching retirement can all create significant windfall scenarios as well.

On today's show, we offer some tips on how to manage life-changing money, including tax planning, dealing with friends and family, and the kind of team that can help you protect your assets.