I never played golf. I never played tennis. I never did anything athletic after I left school. I ate, slept and thought of nothing but the business. That's not good and I wouldn't advise anyone to put that much into it.
Most successful entrepreneurs do.
Joshua Lionel Cowen originally marketed his Lionel train as a store window display to attract customers. When they insisted on buying the trains, he decided to market the trains. Washington Atlee Burpee, founder of Burpee Seed, initially sold purebred livestock and fowl by mail order. As an additional service, he included several types of seeds for his customers' animal feed. When the seeds began outselling his animals, Burpee changed the focus of his business.