I had an interesting experience the other day. I have been using split keyboards for years, but only recently began using a Kinesis Advantage 360 Pro as my daily driver for work; I am so use to the layout now, that in instances where I have to use a non-split, or even my older splits, my fingers fail me entirely - like my brain forgot how to type, my thumbs eagerly searching for the thumb cluster that isn’t there.
Big changes are easy for me to adjust to. I might need a little bit, but going from my Moonlander to a normal staggered keyboard is rarely an issue. Little changes like the Ctrl-button not being where it should on Thinkpads - that gets me every time!