I agree this is its own kind of progress -- knowing what and who doesn't help can be a step toward what and who does.
Poppy Princess, did your former T share anything about the approach or model she was using? In the future you can say, "They tried therapeutic approach X, and it did
not work." Saves time, money and effort...
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My dog

mastered the "fetch" command. He would communicate he wanted something, and I would fetch it.