Why is it sometimes so difficult to forget some people from our lives ..? its kind of depressing , isn't it ?

I will start from beginning . I am a 21 yr old guy . Joined a callcenter this January . A month later I fell in crush with a guy of same age who worked there . I most probably think it was a bromance . I am gay probably , since I don't feel anything for girls . But , maybe my experience with this guy may as well have been gay crush or a bromance . I always longed for him . I think he was my IDOL . I always wanted be to like him , to be with him . This morning I had a dream in which I saw him . I was standing in the corridor of a spacious large house and I was eating standing there . I saw this guy come from other side and I stood silent to see if he would call me first . He went past me and went into next room . I went from behind and hugged him firmly . He turned around and locked his arms around my shoulders and took me outside . So , these kind of dreams re-arouse feelings for that person . I should have forgotten about him by now , I left that job a month ago . But , at the same time , forgetting him sounds horrible . I don't wanna let him go . I would be enrolling for my further studies next month and I may not even get time to think about him then ... what should I do ? thank you