Most days come and go without a single acknowledgement of our age. Ageing, much like growing, happens so gradually that we drift along blissfully unaware of the fact that we are literally decaying. The lines embed that bit further, body parts might ache that bit more but on the whole we’re so oblivious to this that we manage to keep ourselves firmly in denial.

There are, however, some days like today that we’re offered a less than friendly reminder that we are not as young as we used to be. Before I continue and risk the wrath of anyone over 35, I am under no disillusion that I am “old”. I’m firmly on board with the idea that life begins at 40 and I’m truly convinced that my parents are having more fun than ever in their sixties. At the tender age of 31, I can still somewhat unconvincingly boast that I am young.

Back to the day in question. Much of my job consists of spending time with teenagers. I must note that these are not the very young and impressionable, so-awkward-it’s-cute 13 to 15 years olds but the generally miffed and unabashedly honest subsection of over sixteens.  In a typical day, transporting a youngster from A to B, we will battle over both volume control and radio station. I am, without exception, always the loser of this game and on this occasion a very loud Billie Eilish won. Billie warbled “I’m that bad type, make your mamma sad type, make your girlfriend mad tight, might seduce your dad type” and by the end of the 3:14 minutes not only was I firmly convinced that she was the Bad Guy but I was also a bit scared of her. As I heard myself actually say this out loud to the 17 year old girl in the front seat with the bright red, partly shaven DIY hair do, I thought “Christ, I’m old”.

Other insignificant but, on this day, seemingly exaggerated events nodded to my not-so-young-anymore age. I found myself trying to grab at the volume dial without being caught; I found myself willing for the news on the hour; and perhaps most telling of all, I found myself gutted that I was missing the Jeremy Vine show.

The moment, however, which I believe truly sealed my fate was when I declined to join my younger cohort for a Mc Donald’s and proceeded to whip out a miniature sized Tupperware with the Go Jetters on it filled with grapes. If, by now, she wasn’t already convinced that I was 100, this did the trick. I felt immediately disappointed in myself; like that wave that overcomes you when Tesco staff zoom into your face before clicking without any shadow of a doubt “Thinks customer is definitely 25 years old or over.” I always had visions of myself as a “cool mom”, the type Amy Poehler aspired to in Mean Girls as she rocked her pink velour tracksuit and heels. Instead I found myself as a modern day Mrs Doubtfire. The dungarees or width of my eyebrows were fooling no one.

It’s strange, really. We can go through life taking steps that are deemed pretty “adult” without taking much cognisance of this. We might have a mortgage and two kids but it’s the realisation that you prefer The Jeremy Vine Show to chart music that really makes you feel your age. It’s seems then that the number is irrelevant.  Age really is nothing but a number. It’s the subtle reminders that we’ve changed that are much more affecting.  It’s the things that become so synonymous with ageing, like a distaste for loud music or certain musical genres, that speak volumes (no pun intended). Like the literal ageing process, these things happen so gradually (maybe it’s a decibel for every year) we fail to notice them until one day you’re hit with the realisation that you’re scared of a 17 year old girl purporting to be the “Bad Guy”.

Those clichés – “you’re as young as you feel” – have more truth than previously suspected. I’d imagine there’s a 70 year old out there somewhere munching on a Big Mac listening to Billie Eilish who feels much younger than me.  Though who’s to say opting for a packed lunch and Steve Wright’s Golden Oldies should make us any older? If that’s the case, I’ll happily settle for being old any day.