Sitting trot and transitions

We did a lot of sitting trot work today which, to my utter amazement, I did sort of kind of ok.  As in, I wasn't as absurdly stiff as I expected, and I could increase Duke's trot and still sit it.  It wasn't a work of art, but neither am I.
John had us work on forward and back in the canter and trot, and then transitions in the proper frame.  Inside leg to outside hand, and then bend from the inside hand is the short version.  But for god's sake, I don't know why I'm struggling so much with this.  John just gives me the necessary words, and then the very next lap I need all of them again.
He said that his goal in the lesson is to have me feel it, so I can remember the feel.  The feel is very distinct, but I can't put into words what makes it happen.  When I can connect those two, I think things will progress.
We also talked about bending aids, and why sometimes the aid is an inside leg (he's usually falling in over his shoulder; i.e. making the circle smaller) and sometimes an outside leg (I am usually bending his haunches into the circle with this aid) and sometimes the rein (John tries to tell me when he wants me to only bend his neck; he said we used to only bend with the neck, but now I bend his body and then use the neck).
We also talked about the inside seat bone for the canter aid, after I experimented with it in between my last lesson and this one.  It is not a forward and down, but a forward and up - John had to show me twice - it is like the motion of a sitting trot, but then a swoop up.  John said you can use it either to start the canter (when his hind leg is coming under?) or to finish the canter, if he is almost picking it up but then stalling.
I am also having a lot of trouble with my hands.  My outside hand wants to go forward (instead of elbow to hip) and my inside hand wants to drop down and back, which is weird that they're going two different ways, since I can't use them independently.
Riding Duke felt great, but I'm frustrated because I feel like I can only connect the dots when John is there, and I just freakishly get one step or so when I'm on my own.