my ex contacting me then deleting me off fb?

Here is the long story:I dated this guy J for a couple of months in 2008(that fall semester) and then the 2009 fall semester.We called it off in Feb. 2010,rather he did, we went on non-speaking terms,I hit rock bottom after the break up but went back on my feet, did good and made good grades in my classes(we are both in college:me getting my BA in August of this yr and he is working on his MA).So anyways this Monday when I checked my fb I saw that I had a message from him saying something about getting together and meeting up.All I knew is that he had to be drunk because the message was sent at 5am and it sounded as though he was out of it.I answered his e-mail with "Who is this?Is this some stupid joke?I am not trying to offend you" and a second message saying that if he wanted to get a hold of me he knew where he could find on fb,y!mess and aim...After that he never answere and just deleted his account from fb which confuses me..I have not done anything to him but he always said that he never wanted anything to do with me after the break up yet he contacted me this one time then deleted me out of his life for good..What the heck is going on?I have moved on with my life no joke,I have applied for jobs 1 hour away from where he lives and goes to school(we attended the same university) and am in a better place.I know he still resents me for the break up and finding out only months later that last semester I was pregnant and had a miscarriage while he was dealing with his uncle passing away so I am guessing that he resents me even more.

Why does a person who was my best friend(yes we were best friends before we dated) now hate me and resent my friend who was our mutual friend because she is friends with me?