Is it normal that i miss my ex?

My ex and I were friends for a good 9 months before we started dating. After a while the feelings faded away because she kept flirting with this certain girl and when I confronted her, she went ballistic on me, called me names, sent her friends off on me and spent a full two weeks constantly harassing me and even some of my friends who decided to stick up for me. Is it normal that even after everything she did, I still miss her?