In my life, I have received correspondence of all kinds, written with a whole range of purposes. Love letters from boys who came and went; notes in my lunchbox from my mother, when I had been bold and she had been mad and both of us fools were regretful.
There have been letters of rejection from employers who didn't see it in me; scraps of paper passed in class, about the disco at the weekend or with the latest of who was shifting whom; many, many windowed envelopes with hospital appointments laid out inside.
I like getting letters. I like seeing a new email in my inbox. And I know of nobody who doesn't feel some small anticipation at the sound of the letterbox flapping in the morning. Something for my eyes only, from someone who thought me worthy of some words today.
In recent weeks, I have received a different type of correspondence from families who are strangers to me. Hearts broken, grief still clawing away at their door, they have found it within themselves to write.
One mum and dad told me of their son; another mum wrote to me of her daughter. Both young, both beautiful inside and out, both at the start, at the beginning of everything their lives should have held. Both now gone.
The sad stories that these two families have to tell have in common the decision to donate the organs of their children. In fact, in both these cases, the boy and the girl had made their wishes known in conversations with their parents before their donor cards were tragically transformed, from a good intention into a good deed done.
The correspondence from these parents has been welcome. They heard of me through my appearance in newspapers after my transplant. They have wished me well, and I know they mean it.
I have responded to them as best I can. Difficult to make the pen and paper connect and produce some thoughts that may comfort them, but writing back, and giving them the small happiness that comes from the receipt of a letter or an email, that is the least I can do.
I feel in some way as though I owe them, that I owe donor families the world over.
To be indebted like this though, it is no burden at all.