Why are some people happy?

[bobmonk92]

Many people I know always say stuff like "I have no life" or "I am boring" or "I feel like death". Stuff that you say about yourself. My friends in twitter talk like this, but they say they're only kidding. But sometimes I meet people who are genuinely "happy". I think they are called enlightened people. And I heard Buddhism helps you become enlightened. But Buddhists say that you don't have to be Buddhist to BE enlightened, which is why non Buddhist people are happy. So I wondered, well, what's the trick? I wanna be happy and not mean or miserable. I keep hearing smile a lot. But that sounds stupid, cause, peoples will think you have smoked weed, if you're constantly smiling.