Remember the thoughts you had as child? Marvelling at all the things unknown to you and yearning for the answers to all your questions? I never had that wonderful stage of development. I was born me but also... someone else. My head contained not only my own memories and knowledge but that of another person's. I knew how to walk, I had only to train my limbs to it; I could talk once I'd learned how. My vocabulary was one of an adult, right from the start. My parents were confused for many years about me. My explanations rarely helped.
"Mother, I have another person's thoughts. They are not alive though, so don't worry about that. It's not there are two of us stuck in one body. That would be terrible. They are more like memories born into me." Can you imagine your four year old saying that to you? They thought I was possessed. When they did realize I was telling the truth, they began to probe me to find out just whose thoughts I had. They'd lock me up in my room for days at a time with a pen and paper and tell me to document all I knew. Those days were like torture. I still had the mind and wants of a child regardless of what I knew. I wanted to be outside and play with other kids.
My parents saw the error of their ways eventually, after much torment to me, and I was released into the world. My only issue? I kept getting the other memories floating around in my head mixed up with my own memories.