“When you make someone happy, in turn it makes yourself happier as well.” It is like a garden hose never becomes dry as long as it is in use. If happiness runs through us, we have happiness in us.
Someone on Quora asked if there was a step by step plan to become happy. Well, there are several. Arguably the Dhammapada by Shakyamuni Buddha or the Sermon on the Mount by Jesus Christ could be used as such: Their effectiveness does not depend on believing in the divinity of the men who spoke them, they are effective because they represent unchanging truth about human nature. But presumably people want something that is not tied to classical religions, something more generic. And much, much easier. So, what about something super basic. It is not super high concentrated The Fastest Way Ever to Complete and Everlasting Happiness, but it is simple.
1) Each day, try to give others a little more love (respect, understanding, sympathy, thanks) than you receive. Another way to say this is to put a bit more work into other people’s happiness.
2) Each day, learn something new. Preferably something you don’t need to hide under your bed. ^_^; I mean more like improving a skill, or understanding something (or someone) better.
3) Keep an eye out for your own mistakes and spend some time looking for them. Be grateful if someone points them out, or at least investigate whether it may be true.
4) Keep at it. It takes time from you start planting seed till you can harvest fruits, but if you keep at it, sooner or later you will become a happier person and the world a little better than it otherwise would have been.