I have memories that aren't my own
Sometimes there are stories in my brain that I first regard as my own memories - moments that have happened in the past and whatnot. But they feel strange. Then, when I meet someone (or someone I already know) and they tell me about their lives, I realize that the story I had been passing as my own memories is someone else's life's narrative. I imagine this is what it would feel like to have memories of your past lives; they are stories in your brain that no one else put there, but they were not acquired by you, and that they feel natural to you but at the same time they don't match up with your own life.
I am not remembering my past lives, I keep remembering other people's lives; how they felt at a certain moment, what they feel when they look at their spouse, that time they got rejected, a nanny they once had when they were little. The smell of their mother. A movie they saw when they were twelve. When this happens I can't help but realize that I knew something very intimate about other people before they even told me.
Sometimes I feel like I am everyone all at once.