Greek philosopher Aristotle defined happiness or eudaimonia as:
". . . the function of man is to live a certain kind of life, and this activity implies a rational principle, and the function of a good man is the good and noble performance of these, and if any action is well performed it is performed in accord with the appropriate excellence: if this is the case, then happiness turns out to be an activity of the soul in accordance with virtue."
". . . 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."
My own search for happiness has been few and far between. The euphoria always had a shelf-life. As a teenager, I would try and look for it in the safest of places. But I could never capture it. It was always fleeting.