Some time ago, I convinced myself to buy a Typematrix keyboard and to learn how to type using the BÉPO keys arrangement, just for fun. Both the physical layout and the keys positions can be seen on this page.
One fact was very surprising to me: I am now totally unable to use BÉPO on a regular keyboard, and equally unable to use AZERTY or QWERTY on a Typematrix keyboard. My fingers move horizontally or vertically in the first case, missing the keys, or diagonally in the second case leading to the same result.
My brain is stuck with this association and won’t rewire itself.