>>12161578...Oh.
I can't judge whether Sensei is too old or not for being what he is, my dear friend. Time is an uncouth wretch that knows no bounds, and there was always going to be a day when it would hit Sensei as well.
I know not what he has forgotten if he has forgotten anything, but I do wish that we had taken up his offer of becoming masters earlier. It does worry me in a way, but I suppose it will be a non-issue soon enough.
I can tell it's been on your mind for however long though, friend. I don't think you should worry too much, as worrying causes unneeded stress on the body. But, I can see why you're thinking like this...
Is he getting old? Maybe. Does that mean that he should stop teaching? That...is something I don't know.