page 1 of "Essential Teachings" by the Dali Lama

"everything comes from this one basic desire: to obtain happiness and avoid suffering." "We can observe that bodily suffering often comes from te mind, or that if two people are enduring an equal degree of physical suffering, one whose mind is calm and happy suffers much less that one whose mind is agitated and anxious. We can also see that even very fortunate people, who posses all that material well-being can bring, are depressed, anxious, and unhappy... while others, whose daily lives are filled with mis-fortune yet who have a happy spirit and inner peace, give an impression of great serenity. A person whose mind is clear, open, and balanced will envision the frame of mind that she will adopt in the face of inevitable difficulties and will remain peaceful even if she experiences great pain, while a narrow-minded, agitated, and anxious person will unthinkingly become frustrated right away and lack resources when faced with the most minor unforeseen difficulty."