Introduction:

At the start of the film in 1989, Mike O’Donnell (Zac Efron) is the star basketball player in his senior year at Hayden High School, about to play his last game in front of a scout who is there to see if he is worthy of a scholarship to Syracuse University. His girlfriend, Scarlet (Allison Miller), tells him she is pregnant just before he goes on the court, and when the game starts Mike leaves to follow Scarlet to do what he believes is the responsible thing to do, therefore giving up the chance for a scholarship.

20 years later, Mike (Matthew Perry) is 37 and living in L.A. with his geeky software tycoon best friend Ned Gold (Thomas Lennon). He has been kicked out of his home by wife Scarlet (Leslie Mann), who is tired of Mike’s constant regrets and has filed for divorce. Mike’s daughter Maggie (Michelle Trachtenberg) and son Alex (Sterling Knight) want nothing to do with him. After failing to get a promotion at work, Mike returns to his high school to reminisce about better days. Following an encounter later that night with an old man that he had believed to be the high school janitor (Brian Doyle-Murray), he is transformed into his 17-year-old self. Mike takes this as a chance to live the life he always wanted, and with Ned pretending to be his father returns to high school under the name “Mark Gold.” There, he finds out that his daughter Maggie is being pressured to have sex by her basketball-captain boyfriend Stan (Hunter Parrish), who is also bullying his son Alex (duct taping him to a toilet). He decides his real mission is to help his children and begins working with Alex to help him realize his own potential along with the girl of his dream Nicole (Josie Loren) and with Maggie to keep her from ruining her future. During the process, Mike and Stan becomes rivals who can’t stand each other. In the guise of Alex’s friend, he also starts helping Scarlet with yard-work, gaining a new appreciation for his wife.