When the Euro was introduced, I've heard people say things like "older generations will never adapt to the new currency, they'll always refer to the old denominations in their head" – which turned out to be completely untrue.

Adapting to new units is very possible, but it needs a concerted effort. Absent a good inherent reason or anybody capable of artificially creating one, it won't happen on its own.

Wasn't arguing otherwise. If anything, I was illustrating so: I used inch so much, that despite it not being the native unit of length measurement over here, for the specific purpose I used it for it managed to stick incredibly hard.

It was a true concern, I know people who never got used to it. But were 70+ at the time and dead by now, so it eventually gets fixed, yeah.

Did it? I feel like 60+ year olds (current age) mostly still convert (bonus points for not accounting for inflation)