I read somewhere years ago, and it was in my mind that Aristotle claimed that happiness is the by-product of engaging in activity; that happiness is not a thing that can be held in one's hand and it does not drop into our laps as we sit alone in a room. However, I have not found this specific idea in anything I have read of Aristotle on happiness. I remember being profoundly affected by this idea as it explained the need to choose rightly the activities that bring happiness. I want very much to share this perspective of happiness with a 17-year-old girl so she can benefit. Do you know whose idea of happiness this is?