One of the niyamas or “internal observances” that constitute the second limb of yoga is santosa a sanskrit word for happiness and contentment. Being optimistic and cheerful is key to success in yoga. If one feels dour or negative while doing a yoga pose, then coming out of the posture is recommended. By practicing yoga we can learn how to cultivate joy from within without being reliant on external objects for fulfillment.  Uplifting ourselves mentally and emotionally brings a benevolent frame of mind for us to continue our yogic quest.