The idea that you will be happy only after accomplishing something is probably a myth.

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A wise man once said that happiness is just a by product of a life well lived.
I tend to agree with him.
But we mostly think the contrary,
There is a myth that we in some way believe, and it goes like;
Let me do this and this, go through all the struggles and in the end i will be happy ever after, kinda like how it's depicted in most Hollywood movies.
There is no taking away the fact that accomplishing something makes you happier, think of a student graduating after all the sleepless nights doing university coursework. It's always time for joy, throwing parties, the beloved parents are even more happier.. and maybe until a few months when another task of searching for a job sets in.
A football team taking the league title after so many years of handwork.
Is happiness the goal?
Teaching people to be happy is one of the hardest tasks, it's not something to do with following a few steps, some consistence and you will be there, no.
It can be more of a personal thing,
Have you seen texts all over the internet in some self help book calling happiness a goal, it goes like, "it doesn't matter if you are this and this as long as you are happy."
Which is something easy to say than to actually do.
But maybe life is not just all about happiness, maybe it's about embracing all those emotions that come with change, like growth, setbacks and so on
And with every step in life that comes with new problems, it's quite not easy to make happiness your only goal, A college graduate gets better problems after school, he gets a job with a bunch of new problems to solve, and after all the hard work solving those problems, he finally starts a business with again a new set of bigger problems. I see progress in his story as much as he might be facing challenges due to his constant need for growth.

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For most of us looking for happiness, we might be shocked after realizing that we didn't actually know what were really searching for.
It's a quest that never ends no matter how hard you search, but why? because you don't know what you are looking for?, it could be somewhere within you that you are searching from outside?, it could be that maybe you searching for wisdom?. Maybe you don't know that you are actually a happy person?.

Changing the world requires a series of solving better problems

And that my friend does not come with a "don't worry be happy" mindset.
Think of the great artists, musicians, farmers, and pretty much everyone who is trying to make the world a better place, people who contributed to all the civilization that we see of today, they must have gone through all sorts of emotions to make a world a better place for us.
These people were giving to the world, be it in their societies, families,
But they were giving.
Maybe we work to give and that makes us happy.
Think of fathers and mothers who toil just to give to their kids so they get a better life, painters who give to the world their pieces out of hard work.
in most cases we look at the rewards and think they make us happy but in the end what we give is what makes us happy.
It is certainly true that the more we give, the happier we become.

If you ever feel unhappy extensively, perhaps you should start giving more.

Good luck in giving to the world.