thinking about you makes me think of him....

So yesterday I put up a journal about something huge what happened in my life, that caused me the most pain I have ever felt... and ever since I wrote about it I can't stop thinking about my ex.
It's doing my head in so much, because he was the biggest dick ever. He caused me so many problems, got me into so much trouble. We argued constantly, he was into drugs and I hated it.

So why do I still love him?
Why do I smile when I think of his eyes, his smile, his laugh, the way he looks when he wakes up.
Wish I knew why I thought about him so much :(