My T has said that she felt angry about things I'd told her or protective of me for example. I think T's feelings about me (or things that have happened to me) can be helpful in allowing me to see myself from another perspective. So rather than, for example, seeing my younger self as a gross person as I am wont to do, her countertransference offers me an opportunity to see her as an inexperienced, vulnerable person doing the best she could with limited skills.