No pun intended - being young and in love. But to whom? And how much? And what does it do to your relationships? And to your own self confidence? I do like that the movie is not just about one thing. I understand that some people may have and take issue with that and may feel this is overblown (though I also read that some might have liked to have cut this down to a short movie).
I like the acting, I like the twists. Yes the actors may be a bit too old (in real life) than the roles they are playing. But that is nothing new in the film world (see especially the US movies for that). The movie keeps you on your toes - where will it go next? Or rather you may expect it to concentrate on this particular incident, when it already moves on to something else. That includes a powerful speech. Not on par with Spartacus, but ... goes that route! Yes I am Spartacus too (or the equivalent of it - which I wouldn't post for multiple reasons).
And that is maybe one thing that some people may not like: swearing! But young people do that ... well old people do it too - no pun intended.