In reply to TheDrunkenBakers:
Just lucky.
Like so many others he made a lot of money in the first dot com boom making a web service that nobody remembers.
He became fabulously wealthy through Paypal, which was something which was made by a rival company to his, which was bought by a company he co-founded, at a time when he wasn't working there.
He was then brought back in to the company, made a balls up of it, and was ousted from it a second time.
With him gone, the company sorted out their technological and business issues, and eventually sold themselves to eBay which, as the biggest shareholder, made him next-level rich.
If that's not luck I don't know what is.