Knock Knock Math Joke

-Knock knock!
-Who’s there?
-3 period.
-3 period?
–3 PERIOD IMPLIES CHAOS!

Seemed a lot funnier in my head after 27 hours awake.

Or more like 32 hours no sleep.

Then 2 hours sleep.

Then 6 hours no sleep.

Getting really loony.

Update: I got about 10 hours sleep last night and woke up refreshed.