Ex girlfriend had a brain tumour removed and has forgotton me :( ?

We had very strong feeling for each other even still, a lot of complicated stuff happened between us and stuff maybe sometimes that would be best forgot, such as an abortion she had as we are young and hence unsuitable. She had a brain tumour and recently had surgery to get it removed, her memory of the last 6 months up to now is wiped; it's as if i never existed. My question is, do I let her forget these things that hurt, let her forget how she felt, and move on? I am so confused, I don't know what to do; but may be it is best, for it to be forgot?