I just filled in a form and sent it off. It only took a few months before I was told I could be a possible match. I got flown down to London to see a Harley Street doctor. They drew marrow from two bones at the bottom of my back. There was a bit of discomfort, but I also had the feeling I was making someone happy.

My marrow was sent away to Virginia. It was strange knowing that someone had exactly the same DNA as me, that there was a replica of me in them. It's almost like a second life.

Years later, I met my recipient. Rachel was two when the operation happened, four when she met me. I gave her a big hug and said I loved her. She said she loved me back.

Happiness is health and family. It's doing something right and good. I've had some bad personal times, but any time I'm low I think of Rachel's family. I saw how long it took them to rebuild what they had after leukaemia. The transplant was Rachel's last hope. That was back in 1996, and now she's a happy teenager - smaller because of what happened, a bit self-conscious and shy. She's got dark, curly hair, like I used to have. Her happiness makes it over to me in Scotland.

I've got three kids. My own family knows what I did and they're delighted. I'm 44 now. The body is slowing down. There aren't as many stem cells in the marrow, not as many as in a younger man. But if they ever called again, I'd do it.