I dated a guy for about 6 months and our relationship was literally everything I thought I wanted and more and as far as I knew it was like that for him too. Everything clicked. Well out of nowhere one day he broke up with me but didn't have a reason. He then started dating a girl he used to talk to but when I would see him I saw that his eyes still looked full of love like they did before. About 7 months after the break up (by now he was single) I saw him and out of nowhere he told me he broke up with me because he was scared and not ready for the relationship we had. He also told me that he had heard things about me from months after we broke up and was still getting jealous even when he had a girlfriend. He also still felt the need to protect me. I talked to his close friend about it after a while and he told me that my ex said that he felt that I was it for him. Now it's been over a year and he has been single for a while but I know he still occasionally sees the girl he dated after me. We have mutual friends so I see him every few weeks and every time it's just like we never broke up. He has never seen a successful relationship in his family so I'm wondering if that has anything to do with it but my question is why would a guy break up with a girl that he felt he would marry? What could possibly be going through his mind?