I was hesitant to watch this film after the authentic but spirit-crushing Lilya 4 Ever, expecting another innocuous set-up from Moodysson that pulls the rug from under your feet and horrifies you.

Instead, it was one of the most beautiful films I've ever seen. I read on a forum somewhere you couldn't watch it and not be in love with Elin and Agnes and it's completely right - Show Me Love will haunt you for days.

Agnes (Rebecca Liljeberg) has been living in her flyspeck new hometown for two years and still hasn't made any friends, keeping her head down and her mouth shut and just trying to get on. But she's desperately in love with school party girl Elin (Alexandra Dahlström).

As if it's not bad enough being a lesbian, nobody likes her either, and the agony of it will take you back to your own teens no matter what your sexual predilections. Her parents and little brother are understanding and loving, so there's nothing essentially wrong with Agnes' life except for the agony you can see behind her darkly flashing eyes.

Fate puts Elin and Agnes in each other's paths and on a childish whim they decide to hitchhike to Stockholm to escape their boring lives. If Foreigner's I Want to Know What Love is isn't the daggiest song of the 80s I don't know what is, but when it swells into the foreground when Elin and Agnes kiss in the back of some stranger's car it's enough to make you cry.

You'll buy or download it straight away and play it over and over trying to hold onto the beauty of that moment forever. There's never been a sweeter instant in any film where we all feel the burst of relief and excitement at the characters falling in love.

Agnes is over the moon, believing all her dreams have come true. Elin is shocked at hersef for feeling the way she does, avoiding Agnes like the plague and instead hanging around more with her vacuous friend Jessica and Johan – a boy also in love with her but for whom she feels nothing, proceeding to lose her virginity to him to try and ignore her true feelings.

When Elin realises she can't lie to herself any more, she goes to see Agnes and they end up locked and hiding in a cupboard at school while she tells Agnes the truth.

When I look back it's hard to put a finger on what was so special about it. The acting was fine but nothing special, the storyline not especially engaging, and neither leads were teenage models.

I think all it could have been was a writer/director who remembered and understood how much it can hurt being a teenager in love, how world-beating and crushing it can be, how it can exist only in your tiny heart and engulf the whole universe at the same time. Every word of dialogue and frame of the film in infused with that understanding, and the emotional journey is poignant, heart-breaking and beautiful.

It's what Brokeback Mountain tried to be – a film about love where the gender didn't matter. The girls' being gay was never a point of interest or issue of the film, it was all about the stormy waters of the young heart.