I think your therapist might be a bit off the mark. We can TELL others we don't give a damn & even be able to pull it off most days. But holding a boundary like that - where the opinions of others no longer hold sway over our lives - is different than being unkind, uncaring, or uninterested in other Humans. I worked as an ICU & OR nurse most of my career. I learned how to be a patient advocate - let me tell you - NO ONE loves you for that. Even had one boss call me "an insubordinate bitch" but that's not what I was. I was an advocate & I didn't really care what anyone thought of the Mother Wolf who took over my body & mind whenever a patient of mine was in peril. I woke up attendings in the middle of the night, fought with management over supply issues, and went to bat with insurance companies. And I just didn't a single damn what they thought of me.