Never. Especially if the millionaire had some childhood trauma, like growing up poor, or is just being genetically cheap.Whenever I read something like this, I always think "when is enough money...enough?".
You are still not immune from the grass being greener on the other side, even at that level. Except, instead of worrying about being able to pay the bills and buy food, you stress over Abramovich having a bigger yacht.
What I wonder, is where does one keep that money? He sold his shares for 50 million. Where is that money being stored? How do rich people store and distribute their money? Does he store it in some savings account? Can he insure 50 million? Banks have a certain threshold for insurance.