I hope I'm not in the majority when I say this, but my most productive periods (in the sense of producing something) have all involved some kind of death march, almost always self imposed. It's fun, and then painful, and then it brings up a lot of existential angst. Why am I here, and all of that.

He's jwz man, "one of the best programmers" accordingly to Peter Norvig [1]. He can :-)

[1] http://norvig.com/21-days.html

I'm sure the dream of becoming independently wealthy was plenty stimulating.