I'm not sure how to quantify this. Early on, maybe a few months in, my therapist said she didn't know me very well, so I asked her how long it typically takes for her to know a client. She said she's still learning about people in her own life whom she's known for years, and that basically she doesn't feel comfortable thinking she knows all there is to know about anyone. Now, more than a year later, I'd say she knows how I am in session, and how I tell her I am outside of session. She's also seen my work and knows things about me from that.