I see it as one man, and the embodiment of his loneliness. He was secluded as a teenager, and his mind created this.. being form his wish to be together with someone. When he began to contemplate seeing other people, she began to fade, and dissappear. she came to him in the street, as his brain was contemplating being a normal person, the other half of him was unsure. In the hospital ending, he felt content, and attempted suicide so that he would never feel lonely again. After going through the pain, he realised he would be happier after losing her. this explains why she wanted him to live in seclusion. The 3rd ending, the one where he is not happy, nor does he end up in hospital, is when he becomes an urban hermit, living the rest of his life in seclusion.
This is merely my befeif, no flaming please :)
lol awsome glitch: when you upgrade weapons, after upgrading once; wait 1 sec, twice: 2 secs thrice: 3 fourth: 4 fifth:5 sixth:6 and so on. it will never break!
did you know that optimus prime once tried to beat chuck norris in a fight in the arena but couldn't make it. optimus prime shouln't have tried to fight his dad.