verb/a.vwaʁ e.te bɛʁ.se tʁo pʁɛ dy myʁ/
to have been dropped on one's head as a child (to be simple-minded, to be dim-witted, to be stupid)
Literally, “to have been cradled too close to the wall”, with the implication that one's head has been banged repeatedly against it, causing mental impairment.