I'm not an expert, but I think the answer is no, you don't have to remember it from the day it happened for it to be real. I suppose there are some people who intentionally "make it up" for attention, but I'd bet they are few and far between. Plus, their actions, personailities and etc. wouldn't match the story they were telling.

I have no idea if there are such things as repressed memories, but I know that I'm still unable to remember many things I "know" happened. Sometimes I get flashbacks of what occurred, often I'll "see" it in a dream, but they're not true memories. I have heard and I believe that when I feel fully safe, I'll be able to remember them. Until then, I just learn how to deal with the unanswered questions and try to honor my past by living as well now as I can.

I hope you can find a safe place to talk about what you DO remember and hope that you can come to terms with whatever happened to you. PC is a great place for this, but a therapist who has experience dealing with trauma work is also very helpful, and I hope you have/will get this for yourself. You're worth the time and investment!