After completing an apprenticeship to a confectioner in 1873, Milton S. Hershey founded a candy shop in Philadelphia, which failed six years later. After trying unsuccessfully to manufacture candy in New York, Hershey returned to Pennsylvania, where he founded the Lancaster Caramel Company, whose use of fresh milk in caramels proved successful. In 1900, Hershey sold his caramel company for $1,000,000 (equal to $27,936,000 today) and began to concentrate on chocolate manufacturing. In 1903, Hershey began construction of a chocolate plant in his hometown, Derry Church, Pennsylvania, which later came to be known as Hershey, Pennsylvania. The milk chocolate bars manufactured at this plant proved successful, and the company grew rapidly.
— Via Wikipedia. In other words, Hershey was a kickass serial entrepreneur. He started his first company at 16, and when it failed at age 22 he started another one in the same space. After a $28m exit at age 43 he started his third company, which 110 years later now has a market cap of $16b.