Exactly. This isn't the first time it's been popular slang. When I was in school, I suppose sometime in the mid-90s, some variant of saying "herp" in combination with a mocking (usually cross-eyed or eyerolling) expression and hitting yourself in the chest with a bent "spastic hand" was a popular mocking comment to make when you wanted to indicate that someone was being "stupid".

It seems that a surprisingly large number of people this time around simply aren't aware of the origin, though.