Happiness as a weightless nuisance

Happiness is all the fruit flies that spawn from a healthy bunch of bananas. When the bananas have sat then come the myriad of these tiny, weightless nuisances. Now, this is where the analogy has its wings. I, as a relatively easy-to-entertain chaser of all things desirable, find pleasure in capturing these forms of obsolete life. They prove, though, to be fairly difficult to grab out of the air or even squash when they are crawling on a surface. I have deduced it is likely that since their bodies are so light, any motion directed towards them flush them away from grasp. So too, the nature of happiness. It seems to exist as unattainable and flushed away by motion towards. Often, as I close towards a fruit fly and believe for a split second I have possessed it in my grasp, a rush of accomplishment excites my consciousness; yet, as I go to verify my success, I come to find its elusive tendency flitted from me — I am left in disappointment, but for such a short amount of time because quickly I am distracted by another one floating past, another (and honestly equal) opportunity to chase that satisfaction. This experience I’ve had, which may be a phenomenon others share is an adequate correlation of how happiness may exist for some humans. As something chased, allowing bursts of satisfaction before the realization of failure. AND!!! if one does actually manages to catch the happiness, just like the fruit fly, it is crushed and thus eliminated. This discussion and analogy is not a complete truth, yet, unfortunately, is extremely accurate.

So, why may it be true? What about humans allows for happiness to be unattainable most of the time and destroyed upon capture?