How can your thoughts about your thoughts be a C line?

Hi Brooke, I signed up for LCS in March and my dream is to be an amazing coach like you. I watch a lot of coaching calls and take notes because there is so much juicy information and I want to absorb as much as possible. You coached someone about how awful she feels judging her husband for certain things he does which irritate her and this resonated with me because I do the same thing. I didn’t realize how much I was judging myself for my judgement. You said, “our thoughts about our thoughts become our C line” and I thought our C line can only be something that can be proven in a court of law. How can you prove your thoughts about your thoughts in a court of law?