I'm partway through a wilderness medicine textbook from NOLS (formerly National Outdoor Leadership School). Something from the section on burns keeps ringing in my head because it's interesting in its literal truth but also figuratively resonant.

Burns that injure only the epidermis, or that go deeper into the dermis, are generally painful. But deeper ("full-thickness") burns penetrate deeper, injuring the subcutaneous tissue as well. And, although the surrounding area might hurt if it gets a more superficial burn, the deep burn itself isn't immediately painful, because the burn has destroyed the blood vessels and the nerve endings that would convey the news of the damage.

And so that means that there is damage we can take that is so deep that it cuts us off from immediately grasping how much we've been hurt, because part of what it does is remove our capacity to know that. And the recovery will be painful, and more than that, it'll be disorientingly painful, as the fresh shock of the pain will be a sign of the nerves growing back.

I'm middle-aged now so I have decades of my life to look back on. And sometimes I'm telling a story to a new friend, some story I've told dozens of times, and for the first time it occurs to me, "hey, that could have gone differently if that parent/teacher/etc. had taken better care of me," and I feel the fresh pain of new grief over tissue damage I incurred eons ago. The nerves keep growing, and that's a good thing, even if the cost of growth knocks me sideways once in a while.

The weekly MetaFilter free-conversation thread this week spurred me to finally write this down after saying it to friends in several conversations these past few weeks.

I love learning more about medicine partly because it's useful -- I like being capable of helping myself and others with medical stuff, especially first aid -- and because the human body is just a fascinating set of systems. And because it gives me these lenses, these metaphors, that I can try to apply elsewhere.

But also, it grounds me. There is this physical experience that is pretty much the same for everyone who has ever lived. My ancestors, thousands of years ago, got burns and had to treat them. They bled from cuts, and got headaches and blisters and fractures. We know stuff they didn't, but they tried. And throughout history, there have been people trying to heal each other, learning stuff, and I get to inherit that.

(Which makes me feel a little more patient about the delay in NYC releasing the public defibrillator data. Not published yet. I know someone who's working on it, though.)