Jump lesson indoors with Christa

It was an ugly rainy day, so Christa and I jumped inside.
John set up one fence, and we started it going to the right; he started it as a tiny cross rail and moved it up to a hefty (3'8"?) vertical, then we turned around and jumped it going to the left.
Then he lowered it a couple holes and turned it into an oxer.
Duke and I had a few off - either long or too tight, and then we got the rhythm of it. What I had to do was counterbend a little around the turn, then put my leg on, but then half halt, and then count from the turn to the fence. If I counted 1-2-3-4 from the far end of the arena, I could usually get the distance correct.
John said part of it is not letting him drift at the very last couple strides; he said the distance will be good, we'll be coming in steady and then we're 1' off because of the left drift at the end.
The jumps felt freaking huge, but I measured the oxer after and it was only 3'6" and so at best, a couple holes up, it was like 3'8"? Barely even competition height. Ugh - need to retrain my eye.