Did she live in a house made of yellow paper, and eat yellow paper as well? Who paid for the yellow pads? And how did her scribblings on the yellow pad become a best-selling novel? Did she just leave the pad in a bookstore and charge people to read it there?
Maybe starting a business doesn't require much capital, but running it until it becomes self-sustaining (or fails) sure does.
JK Rowling was basically on social security payments from the government which paid for accommodation, food and the like. I'm not sure that would normally be considered capital.
It's income without the need to work for it, which is basically the same thing as having an investor or being able to live off savings, in the sense that it allowed her the time and opportunity to write. If she didn't have those social security payments, she would have had to get a job, and she probably wouldn't have had the time and energy to create the vast amount of wealth she was able to create.
This is a great argument in support of Basic Income. How much wealth is currently not being created because the people who would create it are trapped scraping a living from useless low-pay work?
Or alternatively (more accurately?) praying for the good fortune that someone will invest in your idea. Who knows how many almost-Harry Potters there are in the world?
Maybe starting a business doesn't require much capital, but running it until it becomes self-sustaining (or fails) sure does.