I’m just wondering …. Why not?

Do people ever have a psychotic break and suddenly believe they are something opposite of their deeply held convictions? For example, could a Southern racist have a Psychotic episode and say, “Oh $hit! I’m MLK, JR.!”? Or a jewish person have an episode in which they believe they are the reincarnation of Hitler? Or a homophobe be certain he is actually Liberace??
Y’know, I was just wondering.