Oh man, that’s quite big, nuanced topic. I’ll try to shortly summarize it.
For me, having built foundation means the following:
I am able to generate endless enthusiasm towards my goals, gaining it even after failures
I am feeling absolute confidence in myself (hint: if you can’t freely and easily do something weird like just lay down in the middle of the street, or scream something ridiculous from the top of your lungs in the middle of the street, you are lacking confidence)
I am bold enough and courageous enough to take what I want in life, to fight for my own comfort, protect my boundaries, etc. I.e. I’m not waiting for imaginary permission from someone to try out some new strategy in life, not afraid to talk to someone, etc.
I am only accepting the best from life and have zero tolerance for anything else: I want the best woman in my life and not someone who is just good; I don’t want to have just upper middle class income, I want to be rich. And I’m not using some universal standards, I’m using my own desires. If the best life for you is working 5/2 earning 6 figures, that’s perfectly good as long as it’s really your own desire
I have will to give it my all when working on a task that brings me closer to my goals. Will is a binary thing, you either have it or not just like you can’t be 98% pregnant. If you set a goal to run 1 hour, and at 59 min 43 seconds it got so hard, you stopped/fumbled/etc - you don’t have will
that’s from the top of my head. Of course there are lots of nuances but it would take hours to describe my exact worldview lol, but you get the idea