An investor starting focused work at 25 needs to contribute roughly half the total effort of someone who starts at 30 to reach the same level of mastery by 70. That is not a motivational metaphor. It is the mathematics of compound interest applied to skill, and Albert Einstein reportedly called compounding the eighth wonder of the world. The principle is precise: interest calculated on the initial principal plus all accumulated interest from prior periods grows not linearly, but exponentially. The graph is not a straight line. It is a curve that bends sharply upward, and almost nobody lives long enough in their discipline to see where it goes. Last lecture touched on Monk Mode, but this time, let's explore how consistent deep work leads to mastery and significant achievements over time. That word, compounds, is the entire thesis of this final lecture. Here is the mechanical reality: compound interest grows because interest earned in each period is added back to the principal, forming the new base for future interest. The formula is FV equals P times one plus r divided by n, raised to the power of n times t. Time, rate, and frequency of compounding are the three levers. Of those three, time is the most powerful. Apply that structure to focused work. Your principal is your current skill level. Each deep work session is interest earned. That interest, the new insight, the refined technique, the sharper judgment, gets added back to your base. Tomorrow's session compounds on a slightly larger principal than today's. One hour of deep work daily does not change your life this week. But at 8 percent compounding annually, money doubles every nine years. Skill compounds faster, because the rate accelerates as capability grows. The Rule of 72 makes this concrete: divide 72 by your growth rate to estimate doubling time. A person growing at 12 percent doubles their output capacity every six years. Here is where the numbers become genuinely surprising, Anvesha. Two siblings, same starting point. One adds consistent daily contributions to their principal; the other does not. By year 25, the contributor reaches 750 thousand dollars in accumulated value at 8 percent. The non-contributor reaches 200 thousand. Same rate. Same time. The only variable is regular contribution. In skill terms, that contribution is showing up for the focused session even when the void hits, even when boredom surfaces, even when the day is chaotic. The Daily Highlight is a small, consistent effort that contributes to the exponential growth curve, leading to mastery over time. The counterintuitive reason focus must be treated as the primary vehicle for your life's work is this: distraction is not neutral. Every fragmented hour is not just a lost hour, it is a reduction of the principal itself. Chronic distraction, as covered in lecture one, physically degrades the anterior cingulate cortex, the hardware that enables compounding in the first place. You are not just failing to earn interest. You are eroding the base. Compounding works in both directions. Consistent depth builds exponentially. Consistent distraction degrades exponentially. There is no flat line. Every tool this course has given you, from the Focus Fortress to the Daily Highlight, is designed to support the exponential growth curve of deep work. They are not separate techniques. They are a single system designed to keep the principal intact and the contributions consistent. The architecture is the practice, and the practice, repeated daily, is the investment. Sitting alone in a room for one hour will not change your life, Anvesha. But doing it every day for a year will. That is not inspiration. That is mathematics. The true power of focus is never visible in a single session. It is revealed across years, in the exponential curve that separates the person who protected their attention from the person who surrendered it. You now have the blueprint. The only variable left is time, and time, as Einstein understood, is the most powerful factor of all.