A quote
I am aware that if we test words by our formula, even pleasure is a thing of ill repute, and joy can be attained only by the wise. For “joy” is an elation of spirit,—of a spirit which trusts in the goodness and truth of its own possessions. The common usage, however, is that we derive great “joy” from a friend’s position as consul, or from his marriage, or from the birth of his child; but these events, so far from being matters of joy, are more often the beginnings of sorrow to come. No, it is a characteristic of real joy that it never ceases, and never changes into its opposite.
Seneca·Letter 59 — On Pleasure and Joy (§2)·trans. Gummere