"Don't let the mind run out after external preoccupations. If your mindfulness lapses, then as soon as you're aware of it, immediately pull it back. Don't let it go looking into preoccupations that are good or bad, pleasant or painful. Don't fall in line with them, but don't use force to cut them off."
-Luang Pu Dune ("Gifts He Left Behind: The Dhamma Legacy of Phra Ajaan Dune Atulo")