Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

The Joke

A child calls out from bed asking a parent not to sleep yet because something is the matter. A parent figure comes in asking what is wrong, and the child says something along the lines of wanting the parent to stay. The scene then shifts to "Later" where the parent (now a father figure wearing glasses) is sitting up reading or working, and the other parent asks why he does not just go to bed. He explains, "Dad, I don't get older. Nobody laughs when every dad gets a..." or words to that effect, followed by: "Well, I dunno. I think it's pretty funny to see a dad wandering around in his slippers." The caption suggests the humor of dads staying up late puttering around.

The Humor

The comic plays on the recognizable domestic scene of a child's bedtime stalling tactics, but then fast-forwards to show that the child has grown up to become exactly the kind of parent who stays up too late for no good reason -- the very thing that seemed mysterious when they were a child. The humor is in the cycle of parenthood: the behaviors that seem inexplicable when you are a kid (why does Dad wander around the house at night?) become completely natural when you become a parent yourself. It is a gentle, observational joke about the repetitive patterns of family life across generations.