We’re at an American high school during the late 1980s. It’s a painful place, and so it’s only fair to warn you that this is where you’ll spend the entire movie; not so much at the school itself, but in the society of its students – which is usually painful too. But it’s also magical. High school may be the time when we’re most able to feel deep misery and deep joy at the same time.

Charlie (Lerman), the 15-year-old wallflower of the title, cares less about social awkwardness than most of his peers – mainly because he suffers from periodic black-outs which, when he’s not actually having them, put everything else into perspective. He is counting down the hundreds of days he has left at school when one day he performs a rare, perhaps unprecedented, act of social bravery by introducing himself to one of the senior students, Patrick (Miller), at a football game.

He’s rewarded by being drawn into the social world of Patrick and his half-sister Sam (Watson – who, as I would never have guessed from the Harry Potter films, turns out to be a very good actress indeed), with whom Charlie falls helplessly in love. Obviously, there’s more plot to come; but if the film declared a premature happy ending at this point and nothing much happened afterwards, it would still be worth watching – because I don’t think I’ve ever seen a group of teenagers portrayed so convincingly, yet interestingly, as nice.