Turning a Corner, March 22

At our last Lesson Cheryl wanted me to start pushing Rogo deeper into the corners instead of doing more of a big oval in the arena. Now that he is staying straighter and bending better it's time. She pointed out I wasn't using my inside leg enough in the corners to keep him out. I couldn't do it yesterday, but today, after the first couple of times around, he went waaaay into the corners, so much so that he sort of pinned my leg up against the wall in the corners. At first I thought he was being bad because he didn't want to try something new, but then I thought, no, give him the benefit of the doubt - you're asking him to try to do something new and he's figuring out the aid. So I tried harder to give just the right amount of leg and outside rein and he went just where I wanted him. He wasn't screwing up - I was. He did it a little awkwardly at first, but then better and better. I couldn't believe it. For the very first time he was very maneuverable under me, while keeping a correct frame (for his age / training). I swear I could have leg yielded, and I guess I was leg yielding out to the corner, because I wasn't just steering in with my reins, but moving him out, into the corner with my leg. Yippee!
I tried it at the trot, but he couldn't keep him rhythm when he hot the corners. I don't think I was supposed to do it at the trot yet anyway. I'll ask about it at my lesson tomorrow. I didn't push the matter, just went back to doing it at the walk and giving lots of praise.
Then we worked on trotting and trying for more of a working trot. He was sluggish at first, but his energy level goes up as the ride goes on. I didn't do any longing today, just got on and rode, so he didn't have that warm up.
He was quite willing to pick up his canter today and even did it on his own a couple of times (not a good idea in most instances, but while he's learning I'm not going to discourage him). He wouldn't hold it for long though. Only half way around to the right and even less to the left. I was by myself so didn't push it. He did okay and went into it better than usual, so... It will be time to ask for more soon, but I'll do it when someone is there to help if needed. I wonder if I'm doing something to put him off? Otherwise, why would he be picking it up on his own, wanting to canter, and then dropping it fairly quickly?
Then I asked for a little turn on the forehand (one step each way, went well). Also Cheryl had us try our first walk pirouettes yesterday so I tried one of those each way. Not a great success but not a complete failure either. I finished asking for walking deeper into the corners again, but he wouldn't do it anymore. I dropped the matter, did a little trot, then walked on a long rein to finish. A fairly good ride and the initial work was really exciting.
I longed Dan after that. We worked mostly on walk trot transitions and a little cantering. He did well.