I learned that even when you have a gift to see into the future, you don't bother retelling jokes to get the punchline right after you screwed it up on your first attempt.*
I learned that stage-naming yourself after your two favorite things, Frankenstein and Cadillacs [uh, what??], is considered to be "charming" by some people.
*Seriously, after he got the punchline wrong, I was expecting a sequence where he went back and retold it. Did they just cut that part?