This is possible the dumbest statement ever uttered by a medical student ever:
During second year, we were having a small group session on the liver. At the end of the session, one of my classmates raised her hand:
Her: "Isn't it true that liver transplants aren't that hard to get because people have two livers?"
Attending: [stares at her] ".... Do you mean.... kidneys?"
Her: "Oh. Haha... yeah."
I don't think anyone in that room will ever forget that one.