Speaking of Fischer Black, while he worked quite a bit because he enjoyed it and was given a lot of flexibility due to his reputation, he took great pride in having the smallest percent ownership in Goldman Sachs out of any of the partners while he was there.

He was not a banker himself, and was known to play Super Mario Bros. in his office and spend his evenings at comedy clubs. And he had a bigger impact on finance than arguably any banker since JPMorgan, without working their hours.

Perry Mehrling wrote a great biography of Black which I can't recommend enough.

http://www.amazon.com/Fischer-Black-Revolutionary-Idea-Finan...