[0xCE0]

I think the most important thing in life is to feel how precious and potential it is to be "alive", whatever it means - having self-awareness, consciousness, agency (mind-body-environment interaction).

After this comes the question of how you use/direct this agency - the "meaning of life", so that you feel fulfillment, you know who you are, what your "story" is (and this story can be seen clearly only afterwards).

The state of constant happiness is bad. One needs times of sadness in order to understand/see/remember the state of happiness. One needs rainy days to appreciate sunny ones.

[card_zero]

No, that doesn't work. What is constant happiness bad for? It's not bad for happiness. You might mean that it's not moral, but I can't see the harm in it. Or you might be saying that it's not possible. That sounds more likely: it does seem that people constantly update their standards and expectations in order to maintain a state of discontentment (and, conversely, people will lower their horizons when necessary, in order to maintain a sense of progress).

But then, a satisfactory state of striving ever onward might be called happiness, if you like. Discontentment and all. I suppose happiness has contexts, and the main thing is to be happy in your autonomy, that is, not having your personal business disrupted by catastrophes and interference, in the widest context.