As Anne mentioned, I think that our training somteimes shifts from the techniques that we are working on to, basically, our own state of being.
I remember being at Nishio sensei's seminar (that's the teacher you mentioned, Anne, right?) a couple years back trying to do his jo and bokken stuff and being unable to get some of the finer movements. At that point, I started to work not just with learning the movements themselves but with the frustration of being unable to do the stuff. Frankly, the latter was a much tougher lesson to learn for me.
I think the same kind of thing happens when working with, let's just say, "those kinds of people." We've all run into them. Heck, we've all been them at one point or another in aikido or otherwise.
Me? These days I usually just "shut up and train." Or, at least I try, any way.