Rocks, Pebbles, and Sand refers to an exercise in which a philosophy professor suggested people think of their time like a jar, their priorities as rocks, and everything else as pebbles or sand. If you fill your jar with sand and pebbles first, you won't have time for what matters.
The concept was introduced to me by 📝Drew Houston in 📝Tribe of Mentors who discovered it in 📝The Effective Executive and added "my jar isn’t very big to begin with; am I going to fill it with my rocks or am I going to let other people fill it with theirs?” Houston went on to share📝Other People's Priorities, an email labeling strategy for remaining conscious of his choices.