I hit my head while riding my bicycle and was rushed to hospital. In the ambulance I had severe memory issues and the doctors thought I had a concussion. However, after some brain scans and time in the recovery room, they determined that the part of my brain that stores my personality had become damaged beyond repair. Aside from that I was healthy, and they couldn't do anything else for me, so they let me go. For several weeks I wandered around the house experiencing an extreme form of depersonalisation and like I didn't fit into the world. My parents sent me to therapy. The therapist helped me realise that if my mental issues came from not having a personality, I could resolve this by simply generating a new one, so after some consideration, I did just that. I generated a new personality that is different in some major aspects, including being female. However, this wasn't the end of my problems. Due to the incongruence between my body and my new gender identity, the same therapist reluctantly had to write me a letter for HRT. It's been a couple of decades since then and I feel great!