Is it normal that people living the so called "good life" would willingly give

Is it normal normal that people who are living the good life and enjoying the pleasures of sex and drugs and drinking and rock and roll sometimes voluntarily give all of that up because they have found something better that brings them happiness?
What's lacking in a pleasure filled life that would cause people to trade it for being happy? How can people who have nothing be happy? Where does happiness come from? What is it, even?