Not sure if this is just a break-up or someone had passed but a great way to forget or not miss someone is to change a habit.
I remember when my mother passed, my father rearranged our home, especially our dining and kitchen since that's where my mother always was. My dad bought new dining furniture, change the wallpaper, and basically had a full-on home improvement.

Remember, it's not easy to forget someone you care about, but there are a few things you can do to make it easier on yourself. This will help because it will change your regular routine and give you a different perspective. You can also try talking to friends and family about what you're going through - they may be able to offer some helpful advice. Hang in there - it'll get easier with time.