“All real work is hard. My work happened to be undoable. Morning after morning for 50 years, I faced the next page defenseless and unprepared. Writing for me was a feat of self-preservation. If I did not do it, I would die. So I did it. Obstinacy, not talent, saved my life. It was also my good luck that happiness didn’t matter to me, and I had no compassion for myself.
I would say talent and obstinacy.