Why are you not speaking up? Is it because you see the t as an authority figure? Then, when you become a t, would you expect your clients to be silent and let you talk, since you will then be the authority figure? I think the exercise with the physical boundary line was to show you that you CAN talk. The question is, why do you choose not to? That is many people's problem when they come to therapy. Then they practice speaking in a safe place, with their t (and on pc!), and eventually carry this behavior to real life. The point is to speak politely even when contradicting someone, which is definitely not how some of us were brought up, so we think that even disagreeing is wrong wrong wrong and it's scary to do it and we sure don't do it right the first hundred times or so!