What is he up to? please give me advice!?

Basically, I have an ex boyfriend who exactly yesterday last year broke up with me. he did some horible stuff and told me lies and made me think I had a chance of getting back together again because he's a nasty person and he thought it was funny. This went on for about 3 months after it ended and he would just mess me around about one a month after those 3, I'd add him back on facebook/ msn/ blackberry messenger, he'd start talking to me, cause a fight then delete me even though it was his fault but hed never accept me on facebook. I was really hurt because he meant a lot to me and he ended it for absolutely no reason. Eventually I just gave up and moved on because I knew hed never talk to me again so I haven't talked to him in a while and there's no reason we would want to talk. Then yesterday, exactly a year after we broke up he sent me a friend request on facebook which he never would have done before as every time I added him he ignored. I find it suspicious because we haven't talked in so long and there's no reason for him to add me. What do you think he's done this for?