Ordinarily we are swept away by habitual momentum. We don't interrupt our patterns even slightly. With practice, however, we learn to stay with a broken heart, with a nameless fear, with the desire for revenge. Sticking with uncertainty is how we learn to relax in the midst of chaos, how we learn to be cool when the ground beneath us suddenly disappears.
Pema Chodron (2003). “Comfortable with Uncertainty: 108 Teachings on Cultivating Fearlessness and Compassion”, p.8, Shambhala Publications