Ultimately, everything is a resource allocation problem, the resource being ‘time’. What you do can fit in a calendar. So, how you allocate your time determines everything else, your energy levels, your attention levels, and your output levels.
My version of Paul Graham’s essay Do Things That Don’t Scale is Do things That Compound. Ultimately, all gains in life come from compound interest and the snowball effect. Since the only thing you have that’s common to everybody else is time itself, choose to allocate your time to activities that will compound.
This will require a delicate balance of quality and quantity, but that is what separates the high-performers from the mediocre ones.