I had never watched the 1980s series that 21 Jump Street (2012) is based on. All I knew about it was that Johnny Depp was one of the stars and that made me assume he was a pretty boy non-actor, which was a mistake. So I wasn't watching the the Jonah Hill/Channing Tatum movie out of nostalgia, or even to see them poke fun at the old show. I watched because I had heard it was good.
Jonah Hill is a nerdy loser, Channing Tatum handsome jock. They were enemies in high school, but banded together in Police Academy, based on their complementary talents. When they fail to Miranda a biker, they are busted down to the 21 Jump Street program, a revived project from the 80s. Apparently, the police department ran out of ideas and figured nobody would notice that this is a retread - that's a joke from the movie.
You get a lot of this in the first few acts - grossout gay humor, Ice Cube as the angry police captain: "Well guess what, I am black and sometime I get a little angry!", quick crosstalk from Hill and Tatum. But when the boys go undercover in highschool, they get their identities mixed up, so Hill is the phys-ed and drama class guy, and Tatum has to play brainiac. And now they have a chance to replay their high school days, and get it right. Tatum makes friends with the nerds, who help him understand science (and bug cellphones). And Hill meets a girl who likes him.
Now, this personal growth is taking place in a movie about drugs, dick jokes, and media parody. But still.
In conclusion, the investigation they are on involves a new drug called Holy Fucking Shit, which looks like a lot of fun until it kills you. Have movies always made hallucinogens look like this much fun?