Noticing that your mind is wandering doesn’t seem like a very profound insight; and in fact it isn’t one, notwithstanding my teacher’s kind insistence on giving it a standing ovation. But it’s not without significance. What I was saying in that session with my teacher was that I—that is, my “self,” the thing I had thought was in control—don’t readily control the most fundamental aspect of my mental life: what I’m thinking about.