Pursuit of Happiness

In class this week we discussed the pursuit of true happiness; however, there are many different definitions of true happiness. Is happiness a feeling, health, wealth etc. We tried to give our own definitions of happiness, for a sick person, health may be his true happiness. For a poor person, wealth may be his idea of true happiness. It depends on the person. Also, one needs to have the knowledge of happiness to fully understand the concept of happiness. But then again, different people have different knowledge of happiness. It is like the concept one has to feel pain to feel pleasure. Does on have to encounter sadness to understand happiness?