I started seeing crabs

"Jean-Paul Sartre: after I took mescaline, I started seeing crabs around me all the time. They followed me in the streets, into class. I got used to them. I would wake up in the morning and say, “Good morning, my little ones, how did you sleep?” I would talk to them all the time. I would say, “Okay, guys, we’re going into class now, so we have to be still and quiet,” and they would be there, around my desk, absolutely still, until the bell rang.

John Gerassi: A lot of them?

Sartre: Actually, no, just three or four.

Gerassi: But you knew they were imaginary?

Sartre: Oh, yes. But after I finished school, I began to think I was going crazy, so I went to see a shrink, a young guy then with whom I have been good friends ever since, Jacques Lacan. We concluded that it was fear of being alone, fear of losing the camaraderie of the group. You know, my life changed radically from my being one of a group, which included peasants and workers, as well as bourgeois intellectuals, to it being just me and Castor. The crabs really began when my adolescence ended. At first, I avoided them by writing about them—in effect, by defining life as nausea—but then as soon as I tried to objectify it, the crabs appeared. And then they appeared whenever I walked somewhere. Not when I was writing, just when I was going someplace. The first time I discussed it with Castor, when they appeared one day as we were strolling in the Midi, we concluded that I was going through a depression, based on my fear that I was doomed the rest of my life to be a professor. Not that I hated to teach. But defined. Classified. Serious. That was the worst part, to have to be serious about life..."

Harper's Magazine, Conversations between John Gerassi and Jean-Paul Sartre.