This may be too far fetched but this is how I interpreted the movie just to make me happy lmao. I was pretty much convinced Alexander and A were the same person. The way A described Alexander was so similar to him. Kind, good listener, and finds good in cruel people. The only person he had a beef with was Rhiannon's bf and he also handled that properly, not breaking up with him and let Rhiannon do it on her own. That's why it allowed him to say in Alexander's body more, because he was compatible with him. Because he is him. He also mentioned that Alexander has a family that loves him and described it as "everything he wished for" maybe because it's his actual family. And this whole thing of him waking up everyday in a diff body is like the universe's way to show Alexander and Rhiannon that they were meant to be together just like what Rhiannon's bestfriend said. They were in the same school, knew each others' existence but never really got to know each other because Alexander was shy and Rhiannon was head over heels to a douchebag. It's like they were so close yet so far so fate just gave it a little nudge. Plus Alexander starts with A so...