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.
It just takes me a minute or less to get back into a normal keyboard. Unless that keyboard has shitty switches. Like laptops or cheap keyboards. I never stop hating the mush when I use them.