Apologies to Ledyard Sensei for hijacking the thread! *bows*
And -- I always thought it took a little brain damage to fully appreciate Aiki
No joke. Or it takes at least some difficulty with movement planning/execution (that's why I mentioned dyspraxia). My difficulties are not particularly great, but the main reason I chose aikido over karate, and why I still prefer empty hand techniques to weapons, is that it's easier to move when someone's holding on to me. The opponent's body provides a three-dimensional physical framework within which my body can move. Without that framework, there's just vast empty space and an infinite array of possible trajectories that's just too overwhelming to navigate.
I think a similar effect can be seen in patients after a stroke, when they learn to move their hand again, start by polishing the inside of a pot, movement guided by the pot's edges.