What is most important and what is most important to you?
My science of living = Atheism ..... while least important is religion fucking up living people ...EcoSocialism is most important for USA
I could never work that out, two things. But perhaps making a positive contribution, is the most important thing. That is not I hope, virtue signaling. It is simply that I have reached an age, when I have tried all the fun stuff that interests me, and found that you have just as much fun doing good things as bad or neutral things. So you may as well try to do good by default, even if there is no deep philosophical reason for it.
The other thing which I think is the most underrated, and yet the most important thing of all, is improving your appreciation, which is the best route to joy, and best done by learning. At least it is better than the endless pursuit of novelty. Sometimes people who want to promote it, give it names like, 'awareness', 'spirituality', 'slow living', or 'mindfulness', but they are just talking about methods of getting there, and some methods are better than others, what it really comes down to is, appreciation, knowing how to value what the world gives.