A conversion I once had with a resident during lunch:
Resident: "I don't have any calls for the next, like, two weeks."
Me: "Who's on call tonight, by the way?"
Resident: "I don't know."
Me: (checks schedule) "Hey, YOU are!"
Resident: "I am???"
Me: "Uh, yeah. Good thing I looked it up, huh?"
An R4 at the table: "Well, it's not like it's important to know when you're on call. You'd probably figure it out eventually."