Trying to forget someone we loved is like trying to forget how to walk, trying to forget how to eat, or any other essential function of life. When we truly love someone the love that we felt for that person will be something that dies down over time but never completely goes away. We mustn't try to act like the person that we loved and the love that we shared for that person never existed.
We mustn't let the feelings of old including anger for that person and feeling sorry for ourselves block a new love from coming in either. Instead we can use the past love as a great lesson learned, and use a new found appreciation for love to someone that will love us more than we have ever been loved before, someone way more deserving than the last. We must keep a positive mindset as it pertains to love, stay humble, be cautious, and use our hearts and wisdom to guide us.
We don't have to forget someone we love, what we need to learn is how to accept the verdict of reality without being bitter or sorry for ourselves. We would be better off giving that dedication and love to perhaps someone more deserving.