I have recently taken the book Algorithms, a creative approach by Udi Manber up for reading. The very first chapter kinda sets the stage for what is to follow. There Udi says something. He says that the intuitive solution to a problem (i.e. the one that first comes to our mind) may be inefficient, as it gets applied to larger and more complex instances of it.
So, efficient solutions get counter-intuitive and also complex. What does one learn from this simple, yet powerful statement? It kind of properly sets our expectations, once we start to read and understand things. For example, upon encountering a complex algorithm, we may not understand. But the knowledge that algorithms can indeed get counter-intuitive and complex, gives us patience to put more time and energy into it in an attempt to understand it. And once, you understand it, it further increases the confidence levels.
This applies not just to the algorithms, but to all complex phenomena out there. Be it a complex I/O subsystem, a complex planning system for a city etc.