You are forty-one years old, and you have just had a small argument with your partner about whose turn it was to do the weekly shopping. The argument is, on its surface, entirely unimportant — it will be over within the hour, and you will, in due course, apologise or be apologised to, and the evening will resume its ordinary shape. And yet, somewhere in the middle of it, you noticed something rather strange: you were not, in fact, forty-one. You were, briefly and quite vividly, eight. Your partner was, briefly, not your partner but your father. The sensation in your chest was not a forty-one-year-old's reasonable irritation about logistics; it was the older, sharper, much more bewildering grief of a small child whose efforts, once again, have gone entirely unnoticed.

Have you, in honesty, had such an experience? Have you ever found yourself, in the middle of an ordinary adult disagreement, suddenly inhabiting the emotional weather of a much younger version of yourself, with no clear sense of how you got there or how to get back? It happens, I suspect, to most of us, and far more often than we admit when we are reporting the day to anyone else. We move through the world as adults, ostensibly equipped with adult resources, and yet inside us, like the rings of a tree, are layers of younger selves — each of them carrying a particular wound, a particular unfinished business, a particular emotional milestone we did not, at the time of its arrival, manage to complete in the way our development would have required.

When adult life happens to touch one of those older wounds — and it touches them constantly, often through tiny accidents of language or timing — the younger self, abruptly, takes over the controls of the present moment. The adult does not, in that instant, get to choose; the adult is, briefly, on holiday from her own life, and an eight-year-old or a four-year-old is at the wheel, doing her best with the tools available to her, which are remarkably few.

Which younger selves, I wonder, are still quietly running things in your life? If you slow down enough to notice — and slowing down enough is, admittedly, the catch — you may begin to identify several of them. There is, perhaps, the four-year-old who was not picked up from nursery quite quickly enough one rainy afternoon, and who is, ever since, exquisitely and disproportionately sensitive to anyone being late for things. There is, perhaps, the eight-year-old who tried very hard to be helpful and was rebuked for getting it wrong, and who is therefore, even now, oddly careful never to volunteer too eagerly, in case the volunteering goes badly. There is, perhaps, the fourteen-year-old who was publicly humiliated at a party and who is, decades later, the reason that a particular sort of social occasion still feels — for reasons her older self cannot quite explain — almost physically intolerable.

Have you greeted these younger selves yet, in any deliberate way? Or do they continue to show up uninvited, run the meeting, and then disappear again as suddenly as they came, leaving you afterwards wondering why on earth you over-reacted to a minor scheduling disagreement about groceries?

There is, I have come to believe, a particular and largely unspoken freedom available to people who learn to recognise their own younger selves at work in the present. They do not, when triggered, pretend they were not triggered; they do not, on the other hand, pathologise the trigger and recoil from it. They say to themselves, quietly and almost as a matter of habit, "ah, this is the eight-year-old again"; "this is the four-year-old"; "this is the fourteen-year-old, who has not been seen for some weeks now". They greet the small visitor the way one might greet an old friend who has shown up at the door at an inconvenient hour — with patience, with curiosity, with the simple acknowledgement that the visitor has come a long way to be here, and that she is, in some real sense, family.

What does the small visitor want, in those moments? She does not, in my experience, want to be argued with. She does not want to be told she is being silly. She does not want her feeling to be invalidated by an adult who is herself, in that very moment, somewhere quite else. She wants what every small visitor wants — she wants to be seen; she wants to be heard; she wants, even briefly, to be told that her feeling makes sense in the context of her own much smaller and earlier life; and she wants to be reassured that the adult version of you is, in fact, here now, and will gently take the wheel from this point onwards. Could you give her that, the next time she arrives unannounced?

This is, I think, the inner work of revisiting emotional milestones — and it is rather different from what people sometimes imagine the phrase to mean. It is not about reliving every old wound in cinematic detail; it is not about excavating, one by one, the secrets of one's childhood; it is about developing, slowly, a kind of internal hospitality — about being, for the younger selves who still live in you, the kind of adult who can at last do what no one quite managed to do at the time. Notice. Acknowledge. Make a small space in which the younger self does not have to apologise for existing.

How does this change anything externally, you might quite reasonably ask? It changes, in my experience, rather a great deal. Because the conflicts of your current adult life — the disproportionate irritations, the unaccountable withdrawals, the surprisingly large responses to minor slights — are very often the result of one of these younger selves being woken up and never properly consulted before the adult began responding. When you can consult them in real time, the situation alters; you can return to the actual present argument with the full and unborrowed resources of your actual adult mind; you can, in other words, disagree about the shopping without being in any meaningful sense eight years old at the same time.

Have you experimented with this kind of internal consultation? It looks unspectacular, and it can in fact be performed within a single breath. The next time you feel a disproportionately large feeling rising in an ordinary moment, you might pause and ask yourself, quietly, "how old does this feel?" You may be surprised by the answer; the body usually knows; the body will give you a number, sometimes a precise one. And once you have the number, you can say, internally — "I see you; I know what you are remembering; I am, however, forty-one, and what is happening right now is not, in fact, what happened then". This is not denial; it is not minimisation; it is, rather, the gentle introduction of the adult into a moment that, until that point, has been outsourced entirely to a child.

What might your relationships look like, do you suppose, if you stopped sending the younger selves to do the adult's work for her? I suspect they would become quieter, less explosive, more forgiving. For the explosions in most adult relationships are not, in honesty, between the adults present; they are between the various younger selves on both sides, each one defending an ancient hurt against a partner who has never personally inflicted it. When the adults manage to remain in the room, the explosions tend, on the whole, not to occur.

How do we keep the adults in the room? By, in part, doing the inner work of attending to the younger selves on our own quieter time — by not leaving them to ambush the present unrehearsed, by offering them, in private, the witnessing they did not receive when they first needed it, by going back, in our imagination, to the moments where they were left alone with feelings too large for them, and sitting beside them, and saying, not aloud but internally — "I am here now, and you are not alone, and I am very sorry it took me so long". It is a curious and tender practice, and it does not require a therapist or a programme; it requires only the willingness to take seriously the idea that the past is not over inside you, and that the part of you which still lives there deserves, at last, to be visited. Could you visit one of them this week? You may find that, in the visiting, something quite gently shifts — that the younger self relaxes a little, that the next trigger when it arrives is a fraction less violent, that the argument about the shopping ends rather sooner; and that you walk through the next ordinary Wednesday with the strange new sensation of being, perhaps for the first time in decades, actually and properly your own age.