" Within itself, the mind is already peaceful. That the mind is not peaceful these days is because it follows moods. It becomes agitated because moods deceive it. The untrained mind is stupid. Sense impressions come and trick it into unhappiness, suffering, gladness and sorrow, but the mind’s true nature is none of these things. Gladness or sadness is not the mind, but only a mood coming to deceive us. The untrained mind gets lost and follows these things, it forgets itself, then we think that it is we who are upset or at ease or whatever. But really this mind of ours is already unmoving and peaceful, really peaceful. So we must train the mind to know these sense impressions and not get lost in them. Just this is the aim of all this difficult practice we put ourselves through. "
― Joseph Goldstein , Mindfulness: A Practical Guide to Awakening