Memory is all that is real. I came across something that described how memory is formed and how reading fiction stores memory the same way that experiencing something does (can't find the link now). I feel this and it's why I don't watch things I don't want in my mind. I think that when you have high empathy especially, witnessing can be as powerful as directly experiencing. An experience I had and forgot has no impact on my life now, but a movie I've seen twice is there, a book I've read is there, a song I've heard again and again is there. I am composed of the things that stick.
If I lost all of my memory, I would absolutely not be the same person. The pathways in my brain might make it more likely for me to learn things I had previously learned, but I would be so different. This makes it terrifying to think that my memory is so faulty. I cannot remember my own life and so I cannot learn from it. I don't just lose unimportant memories either -- I lose even ones I would treasure, or ones that would have huge emotional impact. People have told me about experiences I had that I cannot even find a "error: memory missing" tag for, they're just 100% gone. Sometimes if the person I was with can describe in careful detail everything that happened, I can resurrect the memory, but mostly not.
That's why it's so fucking important to me to have an external memory through my journal and my photos. I cannot remember the most beautiful kiss unless I write about it (or thoroughly tell the story more than once). I cannot remember an amazing day with someone I love unless I have made memory tags for it with photos or writing. I am not a full person on my own, because my memory is a sieve that my self-pieces flow out of. I either catch them with my camera or my LJ, or they are lost forever.