"Joyce Carol Oates says somewhere that when writers ask each other what time they start working and when they finish and how much time they take for lunch, they’re actually trying to find out 'Is he as crazy as I am?' I don’t need that question answered."
That's a quote from Philip Roth, which I read just now on rereading one of the books I'd be most inclined to keep if I pared my book-books down to the minimum — "The Writer's Desk." I was going to type out the quote, but I tried Googling roth oates habits and found a whole interview surrounding it — from 1984.
Here's an interview with Jill Krementz, the photographer whose work is collected in the book. My favorite writer-and-desk in the book this one of E.B. White.