"A collection of insults 30" joke

Doesn’t have his belt through all the loops.
Doesn’t have sixteen annas to the rupee.
Doesn’t have the brain power to toast a crouton.
Doesn’t have the sense God gave an animal cracker.
Doesn’t have two neurons to rub together.
Doesn’t just know nothing; doesn’t even suspect much.
Doesn’t know much, but leads the league in nostril hair. - Billing
Doesn’t know which side the toast is buttered on.
Doesn’t put the cross-hairs on the target.
Doesn’t quite sample at the Nyquist rate.
Doesn’t suffer from ear pressure when flying at altitude.
Donated her body to scientists… Before she was done using it.
Downhill skiing in Iowa.
Driveway doesn’t quite reach the garage.
Driving at night with the lights off.