Booze, pot, too much sex, failure in one's private life, too much attrition, too much recognition, too little recognition. Nearly everything in the scheme of things works to dull a first-rate talent. But the worst probably is cowardice.
To make an Army work you have to have every man in it fitted into a fear ladder.. The Army functions best when you're frightened of the man above you, and contemptuous of your subordinates.
I think it's bad to talk about one's present work, for it spoils something at the root of the creative act. It discharges the tension.