That is a complicated question. There is probably a dictionary definition, and a lot of personal opinions.
For me, I would count happiness as a meaningful reduction in anxiety and some ability to feel content. A full night's sleep that isn't interrupted by a couple hours at 2am of lying awake lamenting life choices, lack of achieving goals I had wanted when I was young, missed opportunities, etc. Worrying about the future, are the kids doing okay, are they happy, will they be successful, could I have done a better job raising them?
Objectively I have no justification for the strength of these worries. I am in a great place and I should be able to enjoy that. And yet. The demons have been chasing me since my earliest childhood memories. At best I have fought them to a draw.
