After struggling through something and making a total hash out of it, LL says "Maybe you should leave out the repeats on this one..."
After really pouring my heart into something - I think it was one of the Mendelssohn SWoWs - I turn to LL expecting maybe a little praise, and she says, "How loud would you say you are playing?" Of course I was gobsmacked, it was so totally unexpected, since I thought I was playing so well.
Then over one of the summers, when we were taking a break from lessons, I learned Grieg's "Gade", which I loved. I was going to impress her by playing it at the first lesson in the fall. What does she say? "That should be a G# in the coda, not a G".
Of course she is a great teacher - I took from her for 6 years, and I have sent a couple of adult students to her.