Yes, I have heard that phrase, in a psychology class I took. Could it mean to fake it in your real life enough to allow yourself to get to work every day, take care of your kids, etc.? Because there are essentials in our lives and if we don't feel up to them, maybe pretending/faking we can do them, will actually help us do them. But I don't think a client should fake it in their sessions. In therapy, they should try to be honest and genuine with their therapist. I know it's hard to go from "faking it" by necessity out in your real life, to genuineness/honesty in therapy.

I think being a "good client" does include trying to be honest with the therapist. Other ways to be a "good client" include paying the bill on time and showing up on time for appointments. If one is used to not being genuine, it can be hard to suddenly be honest in therapy. Perhaps just try to look within and catch yourself in session before you tell any "lies," by which I mean, "Oh, I'm fine today," or "I'm feeling OK," or "I don't know" when the therapist asks you what the matter is. Sometimes if I am tempted to tell one of these "lies", I make myself stop and just be silent. If I can't tell the truth (it's too painful, I'm too shy to share, etc), at least I stop myself from saying what is not true. And if I truly don't know what the matter is, I give myself space and silence in therapy to try to figure out what is the matter. Sometimes if the T is patient and lets the silence reign, the answer will come to the client.