If you sit quietly for a moment and just observe what’s happening inside your head, you’ll notice something rather extraordinary. There’s this constant chatter going on. An endless stream of commentary of narration of conversation with yourself about yourself. It never stops. Even right now as you’re listening to me, there’s probably another voice in your head commenting on what I’m saying, agreeing or disagreeing, planning what to think next, wondering if you’ve understood correctly, perhaps even talking about the fact that it’s talking. This internal dialogue is so constant, so pervasive that most people don’t even notice it anymore. It’s like the hum of a refrigerator that you only hear when someone points it out. But once you do notice it, once you become aware of this endless internal conversation, a very natural question arises. Why won’t it stop? Why does the mind insist on this constant talking to itself? And more importantly, who is talking to whom? If it’s your mind talking to itself, then who is the talker and who is the listener? Are there two of you in there? And if there are two, which one is the real you? The one doing the talking or the one listening to the talking? Let me tell you this is not a trivial question. This is perhaps one of the most important questions you can ask about the nature of your own consciousness. Because this internal dialogue, this constant mental chatter is at the root of almost all human suffering. It’s the mechanism by which we create anxiety, worry, regret, and most of our psychological pain. And yet, we’re so identified with it that we think it’s who we are.

— Alan Watts : If You Sit Quietly for a Moment