" The observing self is fundamentally different from the thinking self. The observing self doesn’t think; it is the part of you that is responsible for focus, attention and awareness. While it can observe or pay attention to your thoughts, it can’t produce them. Whereas the thinking self thinks about your experience, the observing self registers your experience directly. "

― Russ Harris , The Happiness Trap: How to Stop Struggling and Start Living: A Guide to ACT