A young man offered me his seat on the train. I was sure he was addressing someone else

Quickly! Fetch the defibrillators! A young man just offered me his seat on the train. At first I looked over my shoulder, sure he must be addressing someone else. But no. While appreciating this gallant gesture, I also wanted to beat him to death with my gym bag. Couldn’t he see I was on the way to a spin class?

I smiled graciously at him, then sat down, too incredulous to comment. Has my visage really deteriorated to such a degree? I feel about 35; it’s only when I look in the mirror and see my dear mother staring back at me that I have to face reality – literally. I may still be young at heart … but I’m clearly slightly older in all the other places.

To compound this sudden burst of age-related angst, when I later asked a shop assistant if I could try on the miniskirt displayed on a mannequin, she laughed so sarcastically I feared arrest by the Mutton Police.

The final insult came when my own progeny whipped my mobile from my hands, convinced that I wouldn’t know how to order my own Uber. I suppose they thought I’d prefer to communicate via carrier pigeon or smoke signal? I’m amazed they didn’t get me a chisel and some stone tablets in order to write my next novel.

The journey from adolescence to obsolescence really does whiz by in the blink of an eye.

Then there’s the looming birthday. I turn 65 in November, which means I’m no longer able to tick the sassy “55 to 64” box on official forms. Instead, I’ll belong to the geriatric “65 and over” category. Pretty soon, even the train driver will be offering me his seat. Should I stop buying long-life milk? And green bananas? I mean, what’s the point?

I’m so surprised at becoming ancient. I always thought it was one of those things that happens to other people. But the journey from adolescence to obsolescence really does whiz by in the blink of an eye. The cruel joke is that just when you finally get your head together, your body falls apart.

But am I falling apart? I’m still running, swimming, cycling and disco dancing till dawn. The only big change I’ve noticed is that I seem to have lost an inch in height. OK, my body might be shrinking but my anecdotes are lengthening. And they’re good ones, too, because by this age I’ve enjoyed the most incredible adventures.

I always thought that the most effective way to stay young is to lie about your age. And that the best way to tell a woman’s age is not to. Or to simply say, “I have no idea how old you are, but you certainly don’t look it.” Post-60, all I want for each birthday is not to be reminded of it.