You don’t necessarily need an IPO and NYSE to be an entrepreneur.
Have an idea for a product people need and are willing to pay for, create an organization that provides that product to these people to a price they can pay and that allows you to properly pay things and people neded to make and continually improve that product. Done. I hear too many stories where people design a company from the ground up for investors to get into instead of thinking about any of the abovementioned points. And then we are surprised that we have one financial bubble imploding after the other.