Dressage lesson at sitting trot

Most of our lesson today, post the trauma of our first go at Prelim at Rebecca Farm, was at the sitting trot, which was pretty cool.  Afterwards, John said it was because Duke said he had a bit of an attitude (although I wonder if it was a little bit me too) and he needed to make him understand that he has a job to do in exchange for the hay he gets to eat.
We started by talking about Rebecca, how each of the three phases went very wrong, even though I felt like I was riding better - and better prepared - than last year.  John said Duke was tense (and thus, I was) at dressage, that the atmosphere is more than I think it is; that for cross country he has no excuse for the first water, but the second water he probably just really didn't see the fence until the last second; and for show jumping he was probably flat, and I really, really should have used Debbie, who John uses because she talks just like he does.  We did learn I can use my crop over fences on xc and the world doesn't end, but that's kind of a pittance lesson.
So we went outside and worked in the dressage arena (small court) and he had me work on 10 meter circles at the canter, then change direction, get Duke rounder and rounder using my legs more than my hands, and then cantering.  From there we did 10 meter half circles and counter canter, with a change of direction.  John also had us go all the way around the long side with 10 meter circles at each letter (at trot).
We spent some time after the first bit of 10 meter circles working on "walking" turn on the forehand each direction.  The aid for this was "inside" bend, inside leg, but - critically - outside leg and outside hand to make the circle.  If I could coordinate all those aids, Duke did great, but as soon as I let one slip, it was obvious.
John had me keep sitting up and sitting deeper, and carrying my hands.  I was amazed that I was able to do it, although it was a bit obvious that concentrating or for transitions, I round my shoulders and curl up.  But - like that one key lesson where I could suddenly feel I was pulling with my hand just before each fence - I could finally feel it, and even feel it before John said it, so long as I wasn't trying to think of 5 other things, I could sort of, half ass correct it.
It was an amazing lesson.  I can't believe Duke can move like that, or that I can actually ride like that.  Of course, John had to tell us each movement and each step, but it was still me getting the movements, which was pretty cool.
It'll be very interesting to see what happens tomorrow when we practice xc and the water.  And even more interesting, what happens show after that.