A recent neurological consultation has confirmed that the mobility difficulties I have been suffering for some months are a consequence of my existing condition, and no other.
My symptoms are apparently quite unusual. My brain seems to have some difficulty processing signals to each leg individually, but can send them to both legs at once with no problems. This explains why during our summer vacation, I was able to swim but not walk.
Receiving information like that is quite sobering; at no point in my life did I ever plan to become a penguin, but it's happened just the same.