I don’t believe ageing is linear: I reckon we have long plateaux, then everything falls apart all at once. I realised this at the close of my harrowing 31st year, when I looked in the mirror and didn’t recognise the sad, grey ghost staring back. I swear one day I was young and moderately dewy with a functioning musculoskeletal system; the next my face imploded, shortly followed by my knee (yes, it was a fun year). There’s a phrase for this kind of sudden ageing in French: prendre un coup de vieux, which feels appropriate, since I was living in France during that first precipitous decline and prolonged exposure to the angry rigours of Parisian life was at least partly to blame.

Anyway, now science is catching up. Earlier this year, researchers identified two “peaks” for ageing at 44 and 60, and now a new paper points to three peaks in brain ageing. At 58, there are changes in proteins associated with wound healing, metabolism and mental health; at 70, it’s age-related brain conditions; and when we hit 78, immunity and inflammation-associated proteins are affected.

This confirmation of my hunch almost makes up for my most recent off-schedule coup de vieux, which featured the sudden drop, in the manner of the new Kendrick album, of varicose veins, a bunion and a gum problem so upsetting I picked a fight with the dental hygienist last week – a fun job lot from the tombola of physical decline.

But what do we do with this new knowledge? Sit around and wait to fall apart on schedule? I suppose the sensible answer is that preventive screening could become more targeted. But how about science offering us some compensatory good news? Arguably, it already has in the shape of the happiness bell curve (which shows we cheer up post-50); but in 2025 I would love it to get more granular. For instance, I want to know precisely when I’ll reach that fabled moment when I stop caring what people think of me. I keep hearing about this blessed liberation, but when, precisely, will it come? Having that to look forward to would be a nice distraction from the bunion.

• Emma Beddington is a Guardian columnist