Full Catastrophe Living: Using the Wisdom of Your Body and Mind to Face Stress, Pain, and Illness
by Jon Kabat-Zinn
"She wondered whether the healthier people had some personality characteristic in common that might be protecting them from the negative effects of high stress. She found that a particular psychological characteristic differentiated those who got sick often from those who stayed healthy. She called this characteristic psychological hardiness."
"If, at some point, you think it is foolish or boring to just sit and watch your breath go in and out, note to yourself that this is just a thought, a judgment that your mind is creating. Then simply let go of it and bring your attention back to your breathing. If the feeling is very strong, try the following additional experiment: Take the thumb and first finger of either hand, clamp them tightly over your nose, keep your mouth closed, and notice how long it takes before your breathing becomes very interesting to you!"