Twenty years ago, star high school athlete Mike O’Donnell (Zac Efron) walked away from a college basketball scholarship when he learned girlfriend Scarlet was pregnant. Today, Mike (Matthew Perry) is depressed that life’s not turned out as he’d hoped. Scarlet (Leslie Mann) is suing for divorce, his kids, daughter Maggie (Michelle Trachtenberg) and son Alex (Sterling Knight), are like strangers, and he’s living with best friend Ned (Thomas Lennon), the nerd who was always bullied at school and is now a millionaire software genius. And still a nerd.

Resigning after being past over for promotion, Mike drops into his old school to reminisce over his glory days, telling a mysterious old janitor how he wishes he could go back and start over.

Driving home, he sees the old man about to jump from a bridge. He stops, goes to help and falls into the river. Arriving home, he cleans up, looks in the mirror and sees his teenage self staring back.

Believing he’s been given a second chance to make good, he persuades Ned to pass himself off as his dad and enrol in high school as Mark Gold. Which, of course, is where he discovers Michelle’s not the sweet innocent he thought and Alex is being bullied by the basketball team, whose obnoxious captain is his sister’s boyfriend. Befriending Alex and trying to steer Michelle right, he also gets to spend time with his unsuspecting wife, realising that the reason he’s 17 again isn’t to fix his life, but to help his kids and make up for being a bad father.

Yet another spin on It’s A Wonderful Life and the ‘you don’t know what you’ve got till you lose it’ message, there’s no surprises here. The film’s careful to soft peddle any inappropriate attraction between teenage Mike, Michelle and the older Scarlet while a rather irritating subplot sees social misfit Ned trying to romance Jane Masterson, the school principal (they share a common Lord of the Rings geekness), but it does have its fair share of amusing and touching moments. Bookending the story, Perry, rather inevitably, has little to do other than mope and then cheer up but, when not having to cater to his High School Musical fans by dancing, shooting hoops, juggling basketballs and flashing his torso, Efron gets to show a nice line in charm and comic timing that suggests he’s this generation’s Michael J Fox. Undemanding feelgood fluff, but none the worse for that.