Jennifer Lawrence proves she is a great physical comedian. The premise is transactional (a woman is hired to date an awkward teen), but the film subverts expectations. The adult humor comes from the gap between her world-weary cynicism and his earnest romanticism. The beach fight scene is a classic, but the ending—where no one "gets the girl" in a traditional sense—feels honest.
Before the gross-out explosion, there was the hangout film. These movies prioritized chemistry over shock value.