TerriBull Read your posts with interest (as always) and was stuck by your mention of stoicism in relation to your son, and therefore felt his getting the tattoo may have been more than a symbolic memory of his brother and might be about externalising the pain of that grief, literally wearing his heart on his sleeve? The change since would fit. Not trying to psychoanalyse your son, just feeling for him and you - such a huge loss.
I've never had a tattoo, got close one drunken night in Amsterdam but mercifully I ducked out. Not because I'm particularly against them per se, but not on me. I have a weird phobia about ink (even washable ink) on my skin and would have freaked out had I woken up sober with a tattoo. Husband has one, he doesn't regret it as such but says if he could go back in time he'd not have bothered.
But people like him are 'randoms' - one tattoo, on a whim, no big regrets. I believe some people see it as an art form, as in living art and an outward expression of who they are and what they represent as a human. It seems to me that seeing it that way it's good to accept that like all things it's an evolution and for some people it's an important method of self expression. But I tend to be very accepting of other people as long as they are decent humans, what they look like is wholly irrelevant to me. But that's me.
As a form of self mutilation (as some have described it) I'm not so sure that should be a cause to condemn it - human beings have been altering their appearance in physical ways since they first stood on two legs, so you could argue it's in our nature as a species. In fact an absence of doing it is almost more interesting - if you consider that it was always a way of telling others who you are and what meant something to you, in short being open, then does it follow that we have been socialised not to show our true selves now? We can present many different 'faces' to our 'tribe' by the use of make up, clothing, hair colour, accessories etc. The art of disguise? A tattoo is a permanent statement of what means something to us and who we are. I think those who see it that way may not ever regret them.
Sorry, bit of a ramble - but yet another really interesting topic that probably needn't be as divisive as it is.