This is not a post on computational complexity. (I can write one, though, and even on communication.)
There have been several incidents in my life that follow a pattern, and I probably should summarize them at least to think about it. It happened to me for some times that I was trying to convey to another person a thought, an idea, or a concept and was utterly failing at the task. It has taken me hours to clarify what I meant, what I wanted to say and what, for me, the logical implications were. In the end, after the task was done and the idea communicated (or so I thought), my first reaction was “Oh wow, this was hard. I think I need a drink now”.
Now one could draw a conclusion that I am simply incapable of communicating my thoughts, but this hypothesis is invalidated by contradicting observations. And the simplest assumption that matches my observation is that it is, in fact, hard to communicate complex ideas; if the person I try to communicate with has a different intuition (even for the same problem!), then the explanations that are completely clear to me may come over as confusing.
This is very, very sad. It increases the amount of communication overhead, it reduces the flow of ideas, and it makes communication sometimes rather frustrating. Furthermore, it constrains the amount of people you have fun talking to. On the other hand, this is a very good reason to appreciate these people more.