"A collection of insults 49" joke

Not an idiot, but plays one in his life.
Not as dumb as he looks, but that would be impossible.
Not digging in the same ditch with the rest of us.
Not done evolving yet.
Not enough brain cells for the Prozac to be effective.
Not enough brains to get anywhere NEAR the gutter.
Not enough change to break a dollar/pound/deutschmark/yen.
Not enough sense to come in out of the rain.
Not enough sense to stay out in the rain. (Like a 60’s flower child.)
Not firing on all four/six/eight cylinders.
Not firmly seated in the socket / screwed in tight.
Not hard-docked.
Not inflated to 90 PSI.
Not Intel Inside. (Or, given Pentium problems, just: Intel inside.)
Not much to show for four billion years of evolution.