Mike O'Donnell (played by Matthew Perry as an adult, Zac Efron as his younger self) is a 37-year-old who feels his life is a disappointment. He blames his unfulfilled potential on a decision he made as a teenager: giving up a college basketball scholarship to stay with his pregnant girlfriend, Scarlett.
Here’s a concise summary of the story of the 2009 English movie 17 Again : 17 again english movie