I have pondered this in terms of my hopes for my son ( and the skills I think he'll need to get there). My thoughts:
Long term relationships (friendship as well as romantic) marked by love, kindness, and respect.
In some way leaving the world better than when you found it. Doing some good for others.
Having passion, whether it is related to work or a hobby.
Having a skill that will allow some financial stability. This one is hard to define, because I do not mean wealthy is a goal, but I think some ability to financially ride out storms is desirable.
What a lovely and perfectly-stated list.
I really can't say it better.
Let me also add--
Liking the person that you are.
Our definition of success has changed radically in the past few years. We really only want self-sufficiency, health, and happiness, at modest levels, for our daughter.
That is not going to look very "impressive" to outsiders any more, in spite of DD's "wasted" potential. That is okay. They aren't living her life. She has at least found a way forward that is consistent with her own inner needs, and that was no mean feat. She gets to define success for herself.