Well, here's an interesting thing: a long time ago soon after my donation in 2013, I gave thought to marking myself with a tattoo saying "No Kidney Left Side" or something similar as a memento.
That never came to anything then, but in August this year someone on Twitter posted a photo of their arm with a tattoo of their kidney donor badge. At once I felt that this was for me! So, a week ago, at the age of 68, I had my first ever (and probably last) permanent tattoo. Here it is, in all its glory:
My wife said that it was my decision, my daughter was a bit surprised, and I haven't yet told my son!