Happiness and unhappiness depend more on one's attitude than external circumstances. Some key factors that can lead to happiness include focusing on positivity rather than negativity, relaxing, caring for one's health, being selfless rather than self-absorbed, awakening love and compassion for others, developing detachment through renunciation and meditation, helping others in need, and devoting oneself to a noble cause greater than oneself. True happiness comes from living a meaningful life and forgetting oneself through service to humanity.