Compounding is often discussed as a financial concept, but it is really a lesson about time. When returns build on themselves year after year, the growth in the final years of a long journey dwarfs everything that came before — not because the rate changed, but because the base grew so large. Warren Buffett has said that the vast majority of his wealth came after his 65th birthday. He started investing at age eleven. The decades in between were the runway. The later years were where time did its most dramatic work. This is counterintuitive. We expect big things to happen fast. Compounding rewards patience — the willingness to do less and hold longer.