Peabody Puns

The film is chock-full of dad jokes (mostly puns). Things like "Marie Antoinette can't have her cake and edict too", "That was disarming" (after the kid rips off a mummy's arm), "She's in denial" (spoken when the girl is in ancient Egypt), etc. The relationship between Mr. Peabody and the boy Sherman is an adoptive one, so the dad element takes center stage.

.....go way back.

when he passes a man who notices him and yells:

"What the heck?! Bears don't know how to ride bikes!

The bear replies: "oh right, i forgot!" and tips over.

My uncle used to tell me this joke as a kid and it took me a while to understand the tiny but valuable lesson behind it.