I think it just takes time. You can still have some feelings for someone years down the line. The only way to move on is to try to focus on what is good and special and unique in any new person that comes into your life, instead of comparing them to the guy from the past. It may also be healthy to totally detach from him - to have no contact anymore - that way your feelings are not being stirred up by him, even on a sub-conscious level. I have been in this position. A totally clean break seems sad but it may be necessary for you to move on to new things. God bless.