How to be happy?

Many people want to be happy in life. How to have happy life? I explore Internet and find the wiki how has some answers for that- Happy life.
Let's study what it say:
Quote: Be optimistic
Firstly it say:"Be optimistic. In the 1970s, researchers followed people who'd won the lottery and found that a year after they'd hit the jackpot, they were no happier than the people who didn't. They called it hedonic adaptation, which suggests that we each have a baseline level of happiness. No matter what happens, good or bad, the effect on our happiness is only temporary and we tend to rebound to our baseline level. Some people have a higher baseline happiness level than others, and that can be attributed in part to genetics, but it's also largely influenced by how you think.  So while the remainder of this article will help boost your happiness, only improving your attitude towards life will increase your happiness permanently. Here are some excellent starting points for doing that:"
My view: To have happy life, we must have the healthy outlook in life. Material gain can not ready give you happy life in the long run if you have wrong mindset.