Mitchell's account of Gould's extravagantly disguised case of writer's block, published as Joe Gould's Secret (1964), presaged the last decades of Mitchell's own life. From 1964 until his death in 1996, Mitchell would go to work at his office on a daily basis, but he never published anything significant again. In a remembrance of Mitchell printed in the June 10, 1996, issue of The New Yorker, his colleague Roger Angell wrote: "Each morning, he stepped out of the elevator with a preoccupied air, nodded wordlessly if you were just coming down the hall, and closed himself in his office. He emerged at lunchtime, always wearing his natty brown fedora (in summer, a straw one) and a tan raincoat; an hour and a half later, he reversed the process, again closing the door. Not much typing was heard from within, and people who called on Joe reported that his desktop was empty of everything but paper and pencils. When the end of the day came, he went home. Sometimes, in the evening elevator, I heard him emit a small sigh, but he never complained, never explained."
Perhaps an explanation does emerge, however, in a remark that Mitchell made to Washington Post writer David Streitfeld (quoted here from Newsday, August 27, 1992): "You pick someone so close that, in fact, you are writing about yourself. Joe Gould had to leave home because he didn't fit in, the same way I had to leave home because I didn't fit in. Talking to Joe Gould all those years he became me in a way, if you see what I mean."