I miss him...

Why is it that everytime I try to think about someone else, he just pops into my head? I mean it doesn't even really matter whether I think about him or not because he does not give a shit about me. He does not even think about me. He cares nothing about me and it is because I am nothing to him....
I'm always there for him and when I'm not... there's a good reason.
He just makes me so mad. The way he walks, the way he talks. The way he smiles at me like there's no problem. Like he isn't hurting me at all.
I guess what makes me so, so mad is that... I know I'm not supposed to be hurting because I already know that this is it. This is how we're meant to be. That this, not being together and him not knowing what I feel... this is our life. And that nothing is ever going to change that. Ever.