If I could have been anybody who's ever existed I'd like to have been Roy Plomley.
He's the guy that invented Desert Island Discs, the British radio programme that been going for ever.
Thanks to one simple idea he managed to live an lifestyle that involved about six hours work a week, leaving him with enough time and money to do all the things he really wanted to do. After he died his wife lived off the royalties. And I dare say their children will too for as far ahead as most of us care to peer into the future.
Just one good idea. Why can't I think of something like that?