Why am I not attracted to him?

This guy and I have known each other since highschool, and we dated for a little while back then but he got into a bit of trouble and our relationship just kind of fell apart. We are now 22 years old and both finishing up school, he is going to be an elementary school teacher, and I am going to be an art teacher.
This guy is good looking, smart, funny, sweet, all of these great qualities, everything I could want. Even conversation is easy, we don’t have those moments of awkward silence, it just flows. And his family is wonderful, I have known them for a long time and as he said “I fit in with them perfectly”.
We have been on six dates so far, and I just don’t feel a spark. My friends think that I am jumping to conclusions because when it comes to romance and dating, I would rather run for the door.
I want some outside advice, I just don’t think there is anything more than friendship with this guy. And this upsets me, I don’t understand how I can just not feel anything for him when he is everything I could ask for.