Sometimes, online, a phrase appears at the very outside edge of your consciousness, then begins to burrow its way inwards in the manner of some horrifying, probably fatal parasite until it’s everywhere and you can’t remember life before it. This has happened in recent weeks with the expression “lock in”.

First, I started seeing people in gym clothes on TikTok attributing their looks (python in a pop sock for the women; slab of meaty bronzed flesh worthy of Barbecue Showdown for the men) to being “locked in”, a synonym for “focused” or “disciplined” (or, some might argue, “tediously self-obsessed”).

I tried to ignore it but “locked in” continued spreading and now it has spawned a new seasonal phenomenon: the “Great Lock-In”. The successor to last year’s wearisome “winter arc” (TikTokers spending the dark months in the gym to emerge buff in spring), the Great Lock-In is an arbitrary set of self-optimisation goals we’re all supposed to sign up for.

“Four months of absolutely ruthless commitment towards yourself,” a red-faced bearded man rhapsodises, jabbing a finger at the camera. Another video (so full of flashing imagery it needs a warning for anyone prone to seizures) explained it more granularly: 10k steps, three to four litres of water, read 10 to 15 pages and get eight hours of sleep daily; do four to five workouts a week; “hit protein goal daily”; “hit cardio, no distractions, focus”. Babe, even drinking that much water would be a full-time (and utterly unwelcome) job for me.

I suppose the Lock-In crew are just a subset of the peppy “new pencils, new resolutions” September sorts, and it’s quite touching, the way they’re trying to get a global platform devoted to listless scrolling to commit to a community project. But does it have to be such a joyless one? I’m watching anyway, because I’m childishly amused that the earnest self-improvement bros and gals have no idea that “lock-in” already has a sacred meaning for Brits: illegal after-hours drinking. A Great Lock-In is surely what happens when it snows heavily at that famously inaccessible pub in the Dales and a tractor needs to come to the rescue?

If they could promise us that four months of “absolutely ruthless commitment” would culminate in limitless cosy pints around the fire for four days, I reckon we’d all be signing up.

• Emma Beddington is a Guardian columnist