Satan being friendly?

Anyone know what it means when your cat is really affectionate? The last few days my cat has been unusually affectionate. Yesterday when doing homework at my desk, he jumped up on it and rubbed against my computer. I thought it was cute, besides the fact that he scared the bejeezus out of me. But seriously, this is NOT an affectionate cat. When I proceed to pet him, he usually gets up and walk away. I used to just think he was a big jerk but now I am used to it. I just can't figure out why he's a fan of mine now. It's a little scary, Milton.

*When we first got Milton we called him Satan because he acted like he had some sort of demon inside of him. He was cah-razzzy. Plus, it kind of rhymes, right? Mil-ton. Sa-tan. Yes?