Guy walks into a studio executive’s office in Hollywood and says, “I’ve got a fantastic idea for a movie. Guaranteed blockbuster.” The executive leans forward in his chair. “Go on,” he says. “OK, so you take Jackass, cross it with It’s a Mad, Mad, Mad, Mad World, set it in an urban environment, put lots of young people in funny clothes while pulling shopping carts around the city like sled dogs and drinking at…