Man, I love being in a jump saddle

We had a jump lesson tonight.  Charlie was his usual fantastic self, after the first trip through the grid which sounded like he just decided to blast straight through as if there were no fences there.
First we did a line of three (?) ground poles that were 9-10' apart.  Then John turned them into a cross rail, then a vertical, and my job was to just stay in my two point and let Charlie figure it out.  I would send him forward on the long side, then look up to my fence, then use my outside leg to balance him, then look up and out to go over the line, regardless of whether it was ground poles or a fence.
The last couple, John said I was drifting to the left (which I could feel) but once he said it, I could focus on it and fix it.  And I did fix it!
That was to the right, so then we did grid work to the left.  This was easier because it was a nice grid - a ground pole, tiny cross rail, pole, vertical, pole, and then a vertical that ultimately became an oxer.
The three takeaways were:
- Keep my back flat; apparently I like to round it over the third fence (I don't know why)
- Keep my head up - keep looking down the line.  Charlie likes to plummet down after the last fence, and it keeps my head from slamming down towards his neck.
- Keep my legs forward.  Instead of rolling forward at the end, make sure to think about my legs being in front of me so they don't flip up after the last fence.
The last few fences we worked on Charlie landing to the left lead.  John put a ground pole out and so I'd land (looking left and with the whip in my right hand) and try to do a flying change over the ground pole.  Charlie didn't, but after a few rounds he voluntarily switched leads by the back door instead of having to go around in a circle.  John thinks he'll get it again as we go back to work.
John said the vertical exercise was a good one to do at home because it makes Charlie think about his feet and keeps me out of the way.
Charlie was soaking wet at the end, so I guess I'm going to have to go ahead and clip him (and he's out of shape).
I forgot to mention from the last lesson that John also suggested using the whip next to my leg, instead of back on his rump, with the leg aid, to intensify it.  He also suggested I try standing up for an hour or so a day, like when I'm reading, as a way to kind of get up and out of my chair but not have to spend an extra hour away from work.
I love lessons with John.  And I got the trailer parked successfully back in its spot, which is what I was the most anxious about.
I felt very - solid and tight - in the jump saddle.  A nice strong sort of feeling.  And John had me start working in a two point, trying to think of the maximum pressure being my upper/lower leg just below the knee - not pinching with the knee, but that spot right below the knee being the primary pressure point.  I was pleasantly surprised with how long it took for my thighs to burn (really my hamstrings), especially after hitting the gym so hard on Tuesday night.