An internet-spread prank that became widely used as a way for assholes to prank the unsuspecting victims who attempt to pronounce it. It is supposed to mean "I so fucking retarded," but many people do not realize this until the damage is done.
(At a local bar in front of many people)
Bro 1: Jimmmmay! Check this out!
(Scrabbles the words "I sofa king we tood did on a napkin)
Bro 2: Alright!
Bro 1: Say those words as loud as you can.
Bro 2: "I SOFA KING WE TODD DID!"
Hot Chick: Why do I even come here..