There is no need to forget what has happened between you two. Time would not help you erase the fond memory you have. Relationship and break-up are parts of our lives and without them, what would our lives become? I remember something Carrie Bradshaw in "Sex and the City" has said:
"Maybe our mistakes are what make our fate. Without them, what would shape our lives? Perhaps if we never veered off course, we wouldn't fall in love, or have babies, or be who we are. After all, seasons change. So do cities. People come into your life and people go. But it's comforting to know the ones you love are always in your heart."
I also remember something that I read long time ago (which is in Chinese):
也許愛不是熱情,也不是懷念, 不過是歲月, 年深月久成了生活的一部份.
The main ideas of these two quotes are: there is no need to forget what has happened. Equally important, don't try so hard to fix what went wrong or try to go back to the best. Life has to move on. I never intend to use these two quotes to bring you alot of comfort. But they are the reminders that give me strength and perspective when I experience setback in relationship (which I personally recently experience some messy relationship problem too!)
Hope everything will turn out well over your end very soon!