'I had been able to spend some time again in my library, moreover with The World as Will and Idea, calmed and in a pleasant frame of mind. And the last thing I expected was that, after an hour or more with The World as Will and Idea, I would suddenly feel a need for my scientific studies, and I had got up and walked out of my library and unlocked the room where I had locked up my scientific studies, that is all my scientific essays and all the essays and books belonging to those scientific studies. For months I had been unable to look at those essays and essays about essays and those books and books about books because I had been in a state of deepest despair.'

from Yes