Oh, where to begin…
I once had a trainer tell both me (at about 11) and my mom about my 4 year old green large pony “I’d get rid of him, but he’s unsaleable. He will never amount to anything, if you want to ride him ever again it will not be at my barn.” I still have said pony, and he wins every class he enters. She was the same person who stood by the jump with a crop when my pony developed a stopping habit. After screaming, “Jump the d*mn jump!” while at her post and my pony running in the other direction, I proceeded to tell her (in tears), “He won’t jump it because he hates you!” It was demanded that I apologize. My mom told me I wasn’t allowed to apologize for what I said, just for taking that tone with an adult. We left shortly after, of course. To this day you can’t stand by a jump and have the pony jump it.
“You’re a fantastic rider, but you need a new horse. This one is cr*p.” Said by a well-respected clinician when I was around 13 after my horse had come back from a tendon injury. I cried, and he personally came to try to make me feel better by telling me how good of a rider I was… but still told me he hated my horse.