The concept of true happiness

I constantly think about the concept of true happiness. Whether its becoming super rich and living in the hills of LA, or accumulating a wealth in order to give back. Theres so many different ways to achieve the concept of true happiness, yet very few seem to actually do it. I see the poorest people in Mexico with the biggest smiles on their face and the wealthy douchebag in his Lamborghini always in a bad mood. I want to know how to truly define this concept of happiness.