The lesson was: "The best way to get into business is to be in business". In other words, the best way to build a successful business is to get started. Do something, anything to get started. You have to do that to get into contact with people and start getting feedback to see what other problems they have.
I noticed the same lesson in this post. Initially, the author was making money from freelancing. But as clients began asking questions and providing feedback, a more profitable idea came to the surface.
Do something. Just get started.
Great post.