What is Deh Deh-deh?
It means you are so dumb
dude1: You Deh Deh-Deh
dude 2: Sorry Dude im not that smart
Man 1: What is 2 + 2
Man 2: 4
Man 1: Oh
Man 2: Deh Deh-deh
See duh, dumb, dee dee dee