Some comedies, regardless of how classic they are, certain people just don't "get." The Jerk is one of those movies. It has nothing to do with Steve Martin, who is (as always) in top form. It has nothing to with director Carl Reiner whom despite some odd project choices is also capable of brilliant comedy. It's just not funny, and all the talent in the world doesn't change that.
It's a decent idea, letting Martin be a poor white man raised by a black family. He decides to see the world, even though he is oblivious to the rest of the world. That's a premise that can carry any comedy, just not this one. The movie just makes absurd turn after absurd turn.
That's not to say things here remain boring. His fight (unbeknownst to Martin's character for a time) against a murderous madman (M. Emmet Walsh) is hysterical. Actually, the entire time he's in the gas station working as an attendant, it's non-stop laughs. That's when the film begins to draw you in.
There's no real reason why anything happens in this movie though. It's not particularly obvious why he's so slow, when the family that raised him - although poor - seems perfectly fine and intelligent. His girlfriend leaves him for no apparent reason, and we never do learn why.
It doesn't take long before he unfortunately moves on from that and just begins to descend into a movie lacking any sort of logic too. Sure, it's easy to buy that he doesn't know anything about the outside world. What doesn't make sense is that he can take down a group of people who insult him (he's suddenly a black belt), and can buy an entire Beverly Hills Estate (without any financial knowledge). He must not be as stupid as the script makes him out to be, and that's the purpose of the movie.
The film didn't need to go this route. It was doing just fine as a clueless guy adjusts to the real world. It's a complete change, and one that ruins the entire experience. (** out of *****)