There are different definitions of happiness according to a person’s level, i.e., the kinds of desires a person has, and whether or not such a person has a desire to seek a higher purpose in life, and to what extent. (For instance, in another Quora thread that has asked this same question, you’ll see how I answer it differently.)
However, in principle, happiness is experienced when a person’s desires are on the brink of being fulfilled, but have not yet been quenched.
In such a state, a person is in a high state of anticipation, like a child who is about to have a birthday.
Therefore, happiness takes place in the anticipation of a reward from life, when we feel as if we are about to be given something very positive and good, like on our birthday. Also, the form that this happiness assumes is different for each person
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