Ray Kroc
At 52, Kroc was a traveling milkshake-machine salesman with diabetes and arthritis. Then a small burger stand in San Bernardino ordered an unusual number of his machines, and he drove out to see why.
What he found — the McDonald brothers' operation — became, under his relentless building, the most recognizable restaurant company on earth. Everything before 52 turned out to be preparation.
Your big break may be one sales call from now.