At the very end of a book I can manage to work for longer stretches, but mostly, making stuff up for three hours, that's enough. I can't do any more. At the end of the day I might tinker with my morning's work and maybe write some again. But I think three hours is fine.
Being famous as a writer is like being famous in a village. It's not really any very heady fame.
I have written a memoir here and there, and that takes its own form of selfishness and courage. However, generally speaking, I have no interest in writing about my own life or intruding in the privacy of those around me.