How much of a topic clicking is just reading from several different sources, rather than one source being particularly "good"? I often joke with a coworker that we don't fully understand a topic until we have read several textbooks/papers on it. It doesn't really matter how good any one text is. I've always wondered what the mechanism is for this. Is is just a certain amount of exposure to a topic? Or is there truly something different enough about the way different authors present material that once you have read from a few, things connect differently?

That being said, how many people are citing specific sources, when it was really just additional exposure to a topic that helped something "click"?