Complexity?

Is “complexity” anything more than a term to denote the extent of human stupidity, or rather, the limits of our perception?

When the rules governing a scenario cannot be read with ease, the scenario is described as being “complex” - it is difficult to understand; it appears to require some sort of deeper understanding. BUT, as we have seen, the rules are not necessarily any more complicated than the most trivial of scenarios.

So if the rules are still trivially simple (think, for example, of the mathematical operations we use to achieve these forms: +, - , /, *), what is it that is more “complex”? The outcome (of our scripts), of course, contain more surfaces, more lines, more etc etc., but is it really more complex - or are we just too stupid?