Dressage lesson and jump explanation

Photos went up from the Aspen derby, and I have a death grip on poor Charlie's face with my hands basically in my lap and no crest release.  John said most likely, Charlie was slugging around, I was leaning back to try to get him to go forward, and over the course of the course, the reins just got longer and longer to where I couldn't give a crest release.
Then he made a point.  He rode the snot out of me.  And then said at the show, if Charlie is stuck and not moving forward, TRY SOMETHING.  Do a 10 meter circle and then canter, or a leg yield, or a lengthening, or anything, just to break up the monotony of doing the same thing and wishing he would do something else.
He did this by starting us on a 20 meter circle, then we'd go down the long side to another 20 meter circle.  Then we'd do the long side on a shoulder in.  Then we'd ask for the canter (with inside hip).  Then we'd do a long side shoulder in at the canter (!!).  Then we'd do a change of direction and counter canter, and then a flying change.  Then some 10 meter circles at the canter where I turned Charlie using his shoulders, and I could feel the start of a pirouette.  Then sitting trot.  Then lengthened trot at the sitting trot.  Then a bigger trot at the sitting trot using my hips, not my legs.
All of this while he had me control my hands - not flapping hands at the sitting trot, but holding steady hands.  And with outside rein/inside rein/outside rein/inside rein lifted (going to the left, to tilt his head in), and leg aids.  It was one of the lessons where the step-by-step was too much for me to feel it all, BUT, I could feel the change it had, especially when we did a half halt with the outside rein and it made Charlie kind of "square up" and balance through his shoulders instead of falling out.
Charlie had one direction where he got mad and was shaking his head then trying to stop, and I'd kick and whip and he'd just toss his head, so that was kind of frustrating, but other than that, Charlie tried to figure out what I wanted and do it.
It was really, really hard, but John said I need to expect more and ask for more, even if I get the wrong thing, at least I am getting a different thing and not just being content with mediocre.