I too have this issue. I've realised that it's when my inner child is present. I revert to having the language & vocabulary of that age. I don't have the words to describe how I feel. I don't understand what my T is saying at that time either. I'm far more articulate when the adult is in the room. My T will change how he speaks to me when he knows my inner child is present. It took a lot of work to eventually accept my inner child & now I recognise when she's around & what she needs.