What keeps us living in either the past or the future?

We live in a world of mental abstraction, conceptualization, and image making — a world of thought. And that becomes our dwelling place. It is a world characterized by the inability ever to stop thinking. The mental noise is a continuous stream. Psychologists have found that 95 percent or more of it is totally repetitive. Perhaps 10 percent of those thought processes, at most, are actually needed to deal with life. Thought can sometimes be very useful [laughter], but in our world it has become obsessive, compulsive, almost like an addiction. People’s sense of identity, of self, gets bound up with their mental concepts and mental images of “I” and “me.”

Eckhart Tolle