An Ex Boyfriend communicates after 18 years.....why?

7 months ago.. i got an email from a someone whose name is not so familiar. he said in his email that he knew me very well and he simply would like to say hi. I got so curious so i asked for his true identity. he did not answer me directly but instead gave me clues about his identity instead. I got mad and did not reply to him anymore. after a few months, i received another email from him saying that he doesn't mean any harm...he's just afraid that i might not talk to him anymore if i get to know his true identity. To make the story short...he revealed himself and he was my EX-BF. We had a very short relationship when we were in our teens...that was 18 years ago. He was the one who broke up me for reasons that my parents doesn't like him. I chatted with him several times..we talked about the past and cleared some issues. he said that he is happily married now, he loves his wife so much. If that is so...why do you think he contacted me?