why dont we retain happiness

Every living entity aspire for happiness and satisfaction. There is no sorrow seeking entity. Every task of every individual is guided by the quest of happiness. But why are we people so unhappy? Haven't we ever found happiness? Of course we have. But the problem is that we dont retain happiness.

Now comes the million dollar question: Why don't we retain happiness? The answer, according to me is that we have never found happiness. What we thought of as happiness is a mere virtual supposition of happiness. Let me explain this with an example. We believe that acquiring a good job will keeps us happy. All of our effort are then directed towards acquiring a good job. We study for years, work hard for good grades, relentlessly search for job and ultimately find one.(if lucky enough...)

What happened after a year! We are really convinced that this job doesn't gives us happiness. Then what gives happiness: maybe promotion, a better paying job, fine colleagues, etc, etc, etc. A good job, which we thought will make us happy for the rest of our life didn't even managed for a year. Why is this? It is because a good job doesn't give us happiness. There is no question about retaining that happiness. As simple as that.

In order to retain happiness, we need to find happiness in the first place. Is it in wife, is it in money, is it in fame or is it in power. After we have decided that 'this' gives me happy and after finding it, I will be happy for the rest of my life, then we can go, search and find it.
This leads us to back to my basic question? Where can we find happiness. If you have found one, please share with me.