The art of living does not consist in preserving and clinging to a particular mood of happiness, but in allowing happiness to change its form ... happiness, like a child, must be allowed to grow up.
Without ambition one starts nothing. Without work one finishes nothing. The prize will not be sent to you. As to methods there may be a million and then some, but the principles are few. The man who grasps principles can successfully select his own methods. The man who tries methods, ignoring principles, is sure to have trouble.
None of us can be free of conflict and woe. Even the greatest men have had to accept disappointments as their daily bread. ... The art of living lies less in eliminating our troubles than in growing with them.