Help ladies! whys she being so odd?

Ok, I had this friend(girl) we started hanging out about 4 yeas ago we got very close, not intimate but close enough to most people thought we were always asked....anywayi went away 2 school , we had issues, we became fiends again, more issues (me being possesive @$$, i was drunk had no right consdierng we werent dating). saw other people, became single again, i sent her flowers told her how i felt, then i got drunk we got into fight a dont rmeember, basicallyi was an *** and shes started seeing someone else over over a year ago i saw her out once and she had a big smile and looked like she wanted to talk..i didnt say anything, i really couldnt just be friends again.i didnt try contacting her except her birthday then i see she has blocked me on aim, is letting my facebo0k request just sit there...so everytime she signs on it says 1 new friend request since i noticed that ive seen her twice one time she we caught eyes fro far away and we siled then last tie i was close and said hi she gave me a phney baloney smile and i just kept walking...thats really shady, whats up wth her? I can see mabye why she blocked me but why after months of no contact? its not like i was emailing, iming or stalkin her anything like that. she was prtty much out of mind until this blocking got my attention. i mean we havent really talked in over a year why would she be mad now? i mean she could have just delclines the friend request