What does it mean to say happiness can be "synthesized"?

One of Aristotle’s most influential works is the Nicomachean Ethics, where he presents a theory of happiness that is still relevant today, over 2300 years later. The key question Aristotle seeks to answer in these lectures is: what is the ultimate purpose of human existence? What is that end or goal for which we should direct all of our activities? Everywhere we see people seeking pleasure, wealth, and a good reputation. But while each of these has some value, none of them can occupy the place of the chief good for which humanity should aim. To be an ultimate end, an act must be self-sufficient and final, “that which is always desirable in itself and never for the sake of something else,” and it must be attainable by man. Aristotle claims that nearly everyone would agree that happiness is the end which meets all these requirements. It is easy enough to see that we desire money, pleasure, and honor only because we believe that these goods will make us happy. It seems that all other goods are a means towards obtaining happiness, while happiness is always an end in itself.

The Greek word that usually gets translated as “happiness” is eudaimonia, and like most translations from ancient languages, this can be misleading. The main trouble is that happiness (especially in modern America) is often conceived of as a subjective state of mind, as when one says one is happy when one is enjoying a cool beer on a hot day, or is out “having fun” with one’s friends. For Aristotle, however, happiness is a final end or goal that encompasses the totality of one’s life. It is not something that can be gained or lost in a few hours, like pleasurable sensations. It is more like the ultimate value of your life as lived up to this moment, measuring how well you have lived up to your full potential as a human being. For this reason, one cannot really make any pronouncements about whether one has lived a happy life until it is over, just as we would not say of a football game that it was a “great game” at halftime (indeed we know of many such games that turn out to be blowouts or duds). For the same reason we cannot say that children are happy, anymore than we can say that an acorn is a tree, for the potential for a flourishing human life has not yet been realized. As Aristotle says, “for as it is not one swallow or one fine day that makes a spring, so it is not one day or a short time that makes a man blessed and happy.” ( Nichomachean Ethics,1098a18) (1)

I thought this gave you a great example of how happiness is synthesized with stoicism. Like stoicism, Aristotle believes that the true acquisition of happiness does NOT come from the 'fleeting' emotions we feel; it is NOT a state of mind, but rather a goal. Happiness as an emotion doesn't last; it's highs and lows, whereas being really happy is something that's just with you............ it's balancing the good and bad.