Day 1 down.
Tasida was right. This IS Horsey Hogwarts. And officially, my inner thigh hurts. First lesson involved a lot of position correction. Mr. Go!-boy is a lot less inclined to lean on me now, and can't pull through me so easily, and I can now sit properly with my pelvic floor pointed down at the saddle and under me instead of tilting. Downside is that my saddle might be too small for me given this correct position, and now that I sit with my legs much longer, I had to let out a LOT of stirrup holes, ha! Looking forward to day 2 after I finish a little work.