22 Bus Twice
I knew a blonde that was so stupid that when she missed the 44 bus, she took the 22 bus twice instead.
Q: What do you call a mentally challenged Chinaman?
A: Sometin Wong.
Still Be Stupid
Insult: If you were any dumber, your head would implode.
Response: If you were a little bit more intelligent you'd still be stupid.
Yo mama so stupid, she tried to talk into an envelope to send a voicemail.
Yo Mama - Under 17
Yo mama so stupid when she went to go see a movie, it said "under 17 not allowed," so she left to get 16 more friends to go with her.