They have their first penny
Check out this link. It's very interesting. Leno says that he never touches his earnings from The Tonight Show, but lives off his earnings as a commedian.
Check out the others, like lovely La Streisand and Warren Buffet, among others.
I personally admire folks for not spending crazy, but being responsible so their kids don't have to tend to them in their old age. :D If my sons are reading this, I'm sure they'll be happy. :p