When you end up dragged out of bed, half asleep, and you still have the wherewithal to school people on more efficient basic usage of vi, you know that vi is now embedded permanently and deeply in the very fibre of your being.
I had some suspicion that the muscle memory wasn’t the only thing that is etched into me, but any doubts that I had, are now gone. vi is firmly paste the “You can pry it from my cold dead hands” level of integration.