If someone hacks your password, you can change it - as many times as you want. You can’t change your fingerprints. You have only ten of them. And you leave them on everything you touch; they are definitely not a secret.
I approach every part I'm asked to do and decide to do from exactly the same angle: who is this person, what does he want, how does he attempt to get it, and what happens to him when he doesn't get it, or if he does?
You will never get to the irreducible definition of anything because you will never be able to explain why you want to explain, and so on. The system will gobble itself up.
So I analyzed that and decided I didn't want to be the president during a depression greater than the Great Depression, or the beginning of a depression greater than the Great Depression.