haunting memeories-good and bad

I expect nothing from this, but just need to put it out there. I wish I could just delete memories, both good and bad from my head! Hard to believe, but even good memories lead to depression. I have a hard time forgetting milestones and anniversarys of stupid stuff, but stuff that affects me and not necessarily even others who were involved. Maybe they remember, maybe they don't. Maybe they don't care. Maybe they can forget them. Maybe they choose to and can forget them. IDK. I must be an over sensitive person. Today is 10 years from something. A crappy something. But it was good then. But I wish it had never happened. Why does this happen? I wish the memories would just go away. I want to forget and carry on but can't.