Some people drive me crazy!

Sometimes you think you know a person and then you find out you really don't. Last week or so, I had a conflict with a person I have known for many years. I mean like I went to school with this girl so let's say 15-16 years. Granted when I left town we were not on the best of terms. Her and I were doing better I thought anyway. Wrong! She said something very wrong publicly on my facebook page. Thankfully no one else saw it. I confronted her with the issue and told her that if she was going to make remarks to me like that she could no longer talk to me. I find out today that she "unfriended" me because of what I said.
My response now is okay whatever! She and I are totally different now. She is into party and drinking all the time like we were still in school and I am more refined. Anyway, I kinda wonder why she did it in the first place. I talked with her brother and he said she does stupid bad things when she is drunk and that she runs her mouth. It frustrated me but I guess some people will never change....