You read a title like this one and think, "Yeah, right! Nobody knows that." Well, that may be true, but you'll have to decide for yourself after reading this. I think there's something to be said for the secret I'm about to share.
What makes life unhappy?
Hardship. Suffering. Trials. These make life unhappy. But why? I think one of the reasons hardships make us unhappy is what we think we're entitled to. We believe we're entitled to be happy. That is the default psychological position we all have. So when suffering strikes, it rubs us the wrong way because we really believe we're deserving of prosperity and health.
What else makes life unhappy?
Missing out on pleasure, excitement, and convenience. So it's not just suffering that makes life unhappy, but when the good stuff is missing we're unhappy. Why? For the same reason. Our default psychological position is to believe we are entitled to pleasure, excitement, and convenience. So when it goes missing, we get disappointed and we're unhappy.
So what's the secret to a happy life? Humility.
Humble people don't believe they're entitled to happiness.
Humble people don't believe they're entitled to pleasure.
Humble people don't believe they ought to be immune to suffering.
The result? While they may not respond to suffering by singing along with Pharrell Williams' song "Happy", they are going to be less vulnerable to despair. Humility is the secret to a happy life.