The grieving process

I saw him today and i swear he looked like he was fighting back the tears. Probably because he has realised what a huge mistake breaking up with me was. Hm, i dunno. But i can't keep thinking of him, i don't want to miss him, i want to hate him. I want to forget about him. I was speaking to a teacher today and they said that psychologists would call it death. I'm in mourning at the moment because i have lost someone and now i am going through a grieving process. It makes sense but shouldn't i be done with the whole process now? Shouldn't he be nothing but a bad memory? OK i know that I'll never forget him but why doesn't he become a memory i can live with and cope with and be able to move on with? Still totally undecided about college.