Because in the end, success isn’t the result of circumstance; it’s the result of response to circumstance. And that’s the heart of self-discipline.
Life continually becomes more and more of a game and less of a grind. The rules are increasingly tilted in your favor because you are designing them.
You quickly adapt to their systems of thought and emotion. Your new normal has fundamentally changed, as has the fiber of your being. Your new environment demands that you continue playing at the level you seek.