You may know more than anyone else in the world about topic A. But surely there are related topics B, C and D that your readers may also be interested in but you don't know quite as much. And then there are topics E and F that you took it for granted your readers already knew backward and forward, because you learned them before embarking on topic A.
Oh. Oops. The question wasn't about readers. It was about serps. Never mind, then.