The future isn't written in the stars. There are no guarantees. So claim your adulthood. Be intentional. Get to work. Pick your family. Do the math. Make your own certainty. Don't be defined by what you didn't know or didn't do. You are deciding your life right now.
The idea of a margin of safety, a Graham precept, will never be obsolete. The idea of making the market your servant will never be obsolete. The idea of being objective and dispassionate will never be obsolete.