Why does this guy keep picking on me so much and not so much on the other girls (he doesn’t like me)?

I mean we knew him since sophomore year and he was in our special education class right. Cool guy but very sarcastic and witty and blunt. He would always give me such a hard time. He would pick on me, be sarcastic with me and whatever. He did that so many times. He did tease the other girls but mostly me. NO he didn’t like me like that. He has crushes on other girls. One time he kept trying to mess with me and push me (not physically) to see if I would react and fight back but he got annoyed and said, “You’re WEAK.” And walked off.
One of my friends stands up to him when he does that but it was playful teasing. He doesn’t mess with her much since she doesn’t take shit from anybody. He says he likes girls that fight back and stand up for myself unlike a spineless wimp like me. That hurt when he said that. My best friend scolded at him for that.
I haven’t seen him since high school. Thank god. A lot of people like him because he’s a cool guy but I didn’t like him too much.
Thank god I don’t see him anymore since we graduated last year.