A brief synopsis... When you're at a loss for words but want to tell someone that he or she is stupid, remember some these quips from our collection here at Aha! Jokes.
His pointers are null / uninitialized.
His puzzle is missing a few pieces.
His reaction time is longer than his attention span. -- Thaves
His root file system isn't mounted.
His seat back is not in the full upright and locked position.
His shared libraries aren't installed.
His signal-to-noise ratio is epsilon.
His spark can't jump the gap.
His spirit guide is a three-toed sloth.
His stack's not very deep / he has an eight-byte stack.
His string's aren't null-terminated.
His strip is demagnetized.
His system administrator is never in.
His train tracks aren't quite parallel.
His URL denies outside access.