In 1929 Jean-Paul Sartre took mescaline – that’s when the crabs started to follow him
Sartre: … I ended up having a nervous breakdown.
Gerassi: You mean the crabs?
Satre: Yeah, 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, “O.K., 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.
Gerassi: A lot of them?
Sartre: Actually, no, just three or four.
Grassi: 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 crabs stayed with me until the day I simply decided that they bored me and that I just wouldn’t pay attention to them. And then the war came, the stalag, the Resistance, and the big political battles after the war.
From the book Talking With Sartre: Conversations and Debates.