I met my younger self for coffee. She wore a crisp white Agnès B shirt and patent ballet pumps; I wore H&M elastic waisted trousers and the T-shirt I wore to the gym the day before. She ordered … hang on, hang on. First, isn’t this a time-travel no-no? And if it’s OK, I have questions. Say I met my 20-year-old self – is it 1995, meaning weak filter in the hippy cafe with cakes that taste like horse food? Or 2025, when every second shop serves violently acidic espressos? (Either way, I need to prepare my stomach.) And how have I lured her out? Because she may be naive, but no way would she agree to coffee with “your future self”. That’s plainly a trap.

This whimsy, you may not be surprised to hear, is a TikTok trend. Based on a poem by Jennae Cecelia, it has been enthusiastically adopted by the youth (how are you dewy-faced babies meeting your younger selves – what are they, foetuses?). The formulaic videos are set to the kind of acoustic crooning that makes my husband instantly switch the radio to Capital Dance and wow, are they earnest about their lost, hurting youthful selves and self-actualised current incarnations. Aren’t gen Z supposed to be jokey nihilists? “We hugged and I told her I am becoming everything she had ever wanted me to be,” goes TikToker @earthtoapryl’s version (2m views). “I told her she’s full of purpose and has taught 10 million people to love themselves,” says another, and if you aren’t cringing your entire body inside out reading that, you’re probably not a gen X cynic.

But everyone loves a growth narrative: the “older self compassionately contemplates young fuck-up” trope is hard to resist. People are forever writing letters to their foolish younger selves as if they’d care; the Guardian ran a whole series in 2017. We need to believe we become wiser and happier; it’s what keeps us slogging on, through the trenches of adulthood, towards the mythic sunlit uplands of the contentment U-curve. No TikTok “younger self” coffee dates I’ve seen go anything like: “She looked at me pityingly; asked pointed questions about my skincare routine and current earnings. She paid, and as she left, I heard her mutter it was no surprise my husband had left me.”

And of course, it does get better, in so many ways. I could do my own: she arrived beautifully turned out, trying to convey an air of remote glamour (reading an article about the mystique of the young Nigella Lawson at an impressionable age was a disaster for me). She struggled to conceal her horror at the potato-faced version of herself who showed up and said she was living back in York and loving it. She wouldn’t have cake with her coffee and wrote everything she ate in tiny neat handwriting in a notebook full of joyless meals (the phrase “scraping of butter” still haunts me). She was brittle and lonely. The older version is a bit gentler, edges rubbed off by life and endlessly getting things wrong; she’s learned to find joy in tiny things (usually, but not exclusively, birds). The younger one would be surprised, I think, that the boyfriend she fought with all the time is now her husband and that we’re mostly very gentle with each other. Sure, there’s all that.

But, at the same time, there’s so much more than skin elasticity going for youth. I know my younger self could teach me things – and not just how to blend foundation properly. She read widely and ambitiously and could concentrate for hours on end. She had expansive thoughts on topics other than lunch. She was sharp, energetic and rarely questioned her own intellect. She was clear about what she wanted from life. The anxious, blurry, unsure, often disappointed-in-myself older version could do with a dose of that.

It would be possible for a person to get quite gloomy thinking about this. But I do know younger me would be astonished (and irrationally resentful) that older me is doing the job she wants, but feels will never be within her grasp – it’s quite salutary to realise that. And if further cheer is needed, there are always 90s faves on Capital Dance. We’d probably both enjoy some of those.

• Emma Beddington is a Guardian columnist