Is it normal to care for a ex boyfriend?

It all started in middle school, i was the new girl in seventh grade.
I had lots of boyfriends in the past,and about a month in a new school i was in a relationship with a boy in one of my classes. He was cute,kind,and very talkative.Then one day on the internet a boy in the same class started talking to me. He said i was very pretty,and from that day on we talked every day in the morning at night and i hardly poke to my boyfriend anymore, So about three months in our relationship we broke up. Then About 3 months later i got in a relationship with the current boy. we dated for 6 years,broke up twice before because of a drug issue he had. then at the end of high school broke up. Now it's
summer and i can't get over him! No matter what i do, see other hotter guys laugh with other guys I cant get over him! His baby face his voice his looks his bright blue eyes! I have brown boring eyes and always wanted blue eyes <3 I've never felt this way with other guys before.Ever. but during high school a lot of rumors said that he did drugs,that he was a pervert,that he checked every girl out,and that he even cheated on me with my number one enemy.I Never believed those lies.Until I found out the smoking was true.Do you think he cheated on me? We stopped talking much in high school. Just here and there.
Is it normal to feel this way? and please any advice to get over him would be great!