A large part of my job is learning. Learning about materials, techniques and styles allows me to be a resource when questions arise. it is important for home inspectors to be "know it alls" about most things relating to homes. Just as important as knowing about stuff is realizing that there is always new stuff to learn about. I am never surprised when I discover something completely new and that is one of the best parts of my job.
The video below was taken on a re-inspection. I had griped about the lack of power to the second outlet in the bathroom on the initial inspection. The sellers enlightened me on the more secretive purpose for this particular outlet!