It is an issue in the movie that Josie is considerably older than her "high school crush" Guy (she is supposed to be 25, while he would be about 17), but actually, Drew Barrymore is 2 years younger than Jeremy Jordan, the actor who plays Guy.
Josie's assignment also resembles the experiences of Cameron Crowe, who went back to his old high school at 21 and wrote a novel and screenplay based on his experience there, which eventually became the movie Fast Times at Ridgemont High.