He's a few planes short of an Air Force.
Your heart's in the right place - it's your head I'm worried about.
He has real polish - but only on his shoes.
He's just like an oil well - always boring.
Moonlight becomes you - total darkness even more!
He's a couple of slates short of a full roof.
Who is your hairdresser, the Bride of Frankenstein?
He'd be out of his depth in a paddling pool.
He has lots of bricks but no cement.
A half-wit gave you a piece of his mind, and you held on to it.
We are not complaining about your shortcomings, but about your long sayings.
There is no vaccine against stupidity.