When someone asks me how old I am, my first thought, before manners intervene, is: what is your business?

I have never fully understood the fuss about age. Outside the few situations where it genuinely matters, medical and legal among them, a person's age is rarely anyone else's concern. Yet the question keeps following me into rooms it has no place in, and I have watched it done to others just as often, in social and working life alike. It is treated as harmless, even friendly. I have come to find it neither. The asking presumes a claim on something that is mine to give or keep. What took me longer to see is that the question is far smaller than the thing sitting behind it.

Let me offer some context that does not usually travel with the question. I am Nigerian, born and raised, and one of the things you come to understand is that a recorded age is not always the precise fact it is taken to be. For many of our parents' generation, and in some of the places they came from, births were estimated, or registered long after they happened. That imprecision did not end entirely with them. It reached into the generations that followed, mine among them. So the number can rest on softer ground than the person asking for it realises. And once you know how soft it is, you begin to wonder what all the weight placed on it is really carrying.

Those who are measured hardest often learn to measure others by the same rule.

Not every asking is an intrusion, and I want to be fair about that. Sometimes it is plain curiosity or warmth. But curiosity is not the same as entitlement, and a question can be perfectly friendly and still be a personal one, no more owed than any other. What I am describing is the sharper kind, the asking that arrives as a measurement. When someone asks in that spirit, they are trying to place you, to work out where you sit in an order they hold in their head. It sorts people by how fully they are to be taken seriously, who counts as a whole and capable person now and who is only on the way to becoming one. The number is the shortcut. What is being weighed is your standing.

This is why age can be used against people at both ends of a life, and often is. The young are patronised as readily as the old are dismissed. These look like opposite problems, and they are not. They are the same judgment reaching two different people, a way of saying that your standing is conditional, that you have either spent yours or not yet earned it, and that until the ledger clears you will be handled accordingly.

I learned this early, when I was starting out and often the youngest in the room, where I discovered quickly that being young got my expertise marked down for it. The people who might have taken me for older, since I plainly knew the work, did something stranger. They began to baby me, and there is nothing endearing about telling a grown woman she is a baby because you can name a larger number than hers. It is condescension in the coat of warmth. But the sting was never the word. It was what the word admitted, that my place had been filed as provisional, on loan, subject to a review I never agreed to.

Some people move through their lives believed by default, their standing assumed, spending it freely without ever knowing it was a gift.

That, I have come to think, is the real subject. Legitimacy, and how unevenly it is handed out. Age is only where I first noticed it. Some people move through their lives believed by default, their standing assumed, spending it freely without ever knowing it was a gift. Others are asked to keep earning theirs, to prove in each new room that they belong in it. I spent a long time in the second group, and longer still misreading why. I thought that if I could only be seen as older, the doubt would lift. It would not have. Being taken for older changes nothing when the belief underneath is that your presence is a thing you must justify. The ache was never about the number.

I want to be honest, because it would be too easy to write this as though I stood outside it. I am no spring chicken, and I have caught the same bias in myself, the quiet filing of other people by a number before they have said a word. And I notice it falls heaviest on women, most often pressed on us by other women, which is the part I have turned over the most. I think I know why. Women have been measured by age more relentlessly than anyone, our worth tied to a narrow and closing window, and those who are measured hardest often learn to measure others by the same rule. We police in one another what we are most afraid of in ourselves. The mask we resent wearing, we hand to the next woman, because we are all standing inside the same arrangement, trying to survive it.

The young are patronised as readily as the old are dismissed.

I have known the other kind of person too, the one who meets whoever is in front of them and grants them their full standing without first checking the number. They understand something the rest of us keep missing, that a person arrives whole, and that their age is the least of what they bring.

So the question was never really how old are you. It is whether we can extend to one another the standing that many of us were made to earn. The living I have done is real, whether or not a stranger can read it on my face. Whether I share the number or keep it, I have stopped feeling I owe anyone an explanation. What I want for myself I owe to everyone else, which is the harder part: to grant people their standing before they ask for it and to treat them as already, fully here and capable, rather than waiting for them to prove it.

Being taken for older changes nothing when the belief underneath is that your presence is a thing you must justify.