A concept can be thought of as a bunch of neural circuits that fire when you are thinking about that concept.
When learning a concept, you often think about it (while reading/listening to/watching some information source on that concept). As you are thinking about it, certain neural circuits are firing. When looking at a source, you get some core values of the concept, but also some false things. The false things can come from 1) mistakes in the source or 2) misunderstandings of the source by you.
If you continue to look at the same source (i.e. take the same perspective), the circuits for both the core values of the concept as well as the false things you are picking up from the source are strengthened. This gives you a very hazy and incorrect picture of the concept. It is important to reiterate - no matter how many times you look at this source, your understanding will never increase because both the good (core values of the concept) and the bad (false things) are being strengthened.
Now, let’s consider you switching to a different source. Looking at this new source still fires the core values circuits, but different false things circuits are fired! No source is perfect, and this source still fires false things, but the key thing is that they are different false things. So what has happened is, your core values have strengthened twice (because both sources have fired them) but the false things circuits are still weak (though you have more of them). Weak circuits disappear very quickly.
Lesson: By looking at several different sources (i.e. by taking several different perspectives) you strengthen good circuits while fading out the bad ones. In other words, you understanding of the concept’s true essense increases.
Remember: When learning a concept, look at several different sources.
Bonus: If you combine this with spaced repeatition (i.e. looking at the different sources at different times), learning is increased even more!
Another bonus: If you have a solid foundation on the pre preqs of the concept, learning becomes much faster because you can connect to old (strong) circuits.
Remember, Synergy is a very powerful thing. You get stuff for free.