What the body holds.

The first news of it comes from outside. A dentist mentions that the back teeth are flatter than they ought to be at your age. Somebody who was awake in the night says you were grinding them. Nobody is more surprised than you. As far as you were aware you were asleep, and whatever the jaw was doing, it was not doing it on your instructions.

The NHS has a page on teeth grinding, and at the top of its list of causes it puts stress and anxiety, naming that as the most common one. It is an unusually plain sentence for a public health page, and it is worth staying with, because the grinding is not a thought and it is not even a feeling. It is a muscle doing a piece of work at four in the morning, and the person it belongs to is not present.

The breath goes the same way and is easier to catch in the act. The inhale happens. The exhale waits. Something arrives, a message, a name on a screen, a door going in the corridor outside, and the air is held at the top until the thing resolves. The thing does not resolve. So the air stays up there and gets paid out slowly, in instalments, while the next one is already arriving. Half a breath is not a fault in the breathing. It is the posture of somebody waiting to find out, and it is held because finding out has been about to happen for a long time.

The same phrase arrives for all of it, and nobody is taught it. Without realising. The jaw without realising, the breath without noticing, the hands without knowing they were doing it. It is worth seeing what that phrase does, because what it does is generous. It takes the charge away. There is nothing to admit to and no slackness to own up to, because the thing was not done on purpose and was not available to be noticed while it was happening. Whatever this is, it is not a failure of self-knowledge. It is a record written in a hand you cannot read while it is still writing.

The shoulders are the clearest case and the one with the least to say for itself. They are up. Told to come down, they come down, and they stay down for roughly as long as the attention stays on them, which is four or five seconds. Some while later they are back where they were and there is no record of them going. This is where the ordinary phrase is better than any clinical one: my body won't let me relax. Not can't. Won't. A refusal, politely attributed to something that is not quite you, which is the only honest way to describe being overruled by your own shoulders.

A refusal of that kind is not open to argument, because it was never the result of one. Nothing up there was reasoned into position. It is not a belief about danger that could be corrected by better information about danger. It is a setting. You can be entirely satisfied at two in the morning that there is nothing to be braced for, and win the point convincingly, and the shoulders will not have been listening, because they were not party to the discussion and have no access to its minutes.

And they were right once, which is the part that gets left out. Holding is not a mistake. Somewhere behind this there was a stretch when being braced was simply accurate, when the next thing genuinely was about to arrive and meeting it unready would have cost something real. A year like that, or several of them, or a childhood. The holding was the correct response to the situation. It worked. And working is how a response becomes a default.

What never happened was the announcement. The stretch ended on no particular date, and nobody came round to say the situation had changed and the position could be stood down. That is the whole of the mystery, and there is less in it than people expect. The guarding carries on because nothing has told it to stop, and it will carry on carrying on, indefinitely and without complaint, for as long as nothing contradicts it.

There is also a reason none of it can be seen from the inside. A constant is invisible to whoever is inside it. Noticing needs a difference, and there has not been one for years: the jaw at rest and the jaw at work feel identical, because the jaw at rest is a thing that stopped happening. That is why the news has to come in from a dentist. Not because the body is secretive. Because it is the background, and nobody sees the background.

It explains an arrangement that otherwise makes no sense, too: exhausted, and wide awake. There is no contradiction in it once you allow that something is still on duty and was never stood down. Being tired is a fact about the person. Being on duty is a fact about the guard, and the guard does not report to the person.

One more thing, because this is where the subject usually goes and it is the wrong direction. None of it is a message. Nothing is being communicated through the jaw. There is no meaning folded into the shoulders waiting for the right person to read it out, and no account of the past that has to be recovered before anything can move. It is simpler than that, and less interesting. A muscle was asked to stay ready. It agreed. The request was never withdrawn.

Which is why understanding it changes nothing by itself, and anybody who has tried can confirm that. Reading about the jaw does not open the jaw. You can hold a complete and accurate account of why your shoulders are up, in considerable detail, with your shoulders up. The explanation and the holding are kept in different places and do not correspond, exactly as the argument at two in the morning did not.

If it ever gives, it does not give because it was persuaded, and nothing is done to it. There is no procedure in this. The jaw lets go a fraction and takes it straight back. One breath goes further out than the last several thousand and then the matter is dropped. Nothing about it is impressive and there is nothing to report afterwards. The only unusual feature of any of it is that it was not arranged.

At some point a dentist will say something about the back teeth. You will be surprised. Then you will remember having been told before, by somebody else, a few years ago, and that nothing in the interval was decided by you.