That doesn't sit right with the fact that we remember passwords or other sequences with our fingers or can type whole paragraphs without minding the keyboard.

That doesn't sit right with the fact that we remember passwords or other sequences with our fingers or can type whole paragraphs without minding the keyboard. There might be a threshold to be good with an input method, but it feels contrived to me to assume that only the most basic ones can be mastered and become intuitive.