The only thing a billionaire can never have

True story, Word of Honor: 
Joseph Heller, an important and funny writer 
now dead, 
and I were at a party given by a billionaire 
on Shelter Island. 
I said, "Joe, how does it make you feel 
to know that our host only yesteray 
may have made more money 
than your novel Catch-22 
has earned in its entire history?" 
And Joe said, "I've got something he can never have." 
And I said, "What on earth could that be, Joe?" 
And Joe said, "The knowledge that I've got enough." 
Not bad! Rest in peace!

Kurt Vonnegut
The New Yorker, May 16, 2005
via The No Asshole Rule by Robert Sutton