I’ve always loved this joke of his:
“I woke up one morning and looked around the room. Something wasn’t right. I realized that someone had broken in the night before and replaced everything in my apartment with an exact replica. I couldn’t believe it…I got my roommate and showed him. I said, “Look at this–everything’s been replaced with an exact replica!” He said, “Do I know you?”
I like this twist on the Capgras delusion!