These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Big Lipped Alligator Moment: There is a line of a dialogue Adam asking Beth flat-out if she was sexually excited by being around wildlife that is said once and then never ever brought up again.
Adam sort of explains it, as he was told by his psychaitrist to speak his emotions out loud more often, and because he was feeling aroused at the time (for whatever reason), he asked her if she felt the same way, thinking it wouldn't be quite so awkward if they both felt the same thing. Needless to say, it didn't quite work out that way. As for it never being brought up again, that was probably a moment they both just wanted to put behind them and forget.
Tear Jerker: The portrayal of Asperger's is pretty good, so for some Aspies it can be an eye-opening look at how other people experience them.
There are some general tear-jerking moments, too. For example, the "Dumb Adam" scene.
What an Idiot: Adam doesn't even try to explain himself while waiting for Beth outside the school where she works, resulting in the police assuming that he's a pedophile and holding him at gunpoint. Sure, Aspies sometimes have difficulty expressing themselves, but again. He doesn't even try.
It's pretty obvious in the scene that he's panicking too hard to talk. It happens.
The Woobie: The film plays up the idea that Adam's life is sad and complicated.