17 Again (movie, 2009)

On the brink of a midlife crisis, 30-something Mike O'Donnell wishes he could have a "do-over." And that's exactly what he gets when he wakes up one morning to find he's 17 years old again. With his adult mind stuck inside the body of a teenager, Mike actually has the chance to reverse some decisions he wishes he'd never made. But maybe they weren't so bad after all.