As a society this days, I think we're a bit conceited. Surrounded by and immersed in this matrix we have created, we are distanced from the systems with which we regularly interact, and inured or ignorant of the complexity beyond so many of the things that we take for granted. This is not only applicable to physical things and technologies - it applies equally well to social structures, institutions, governments, administrative systems, and so forth - but it is easiest to understand and perceive in the context of technologies. I definitely suffer from this conceit, wherein I start to think that I understand enough about so many different things that I should be able to reverse engineer or recreate just about any system I might encounter, at least on a theoretical level. Whenever I start to think that way, I give myself what I've taken to calling "The Pen Conceit Lecture."
It doesn't come up often, but occasionally I'll have someone ask me to write them into one of my stories. They'll say that they don't care what I do with the character, but that they want to be in there somehow. I refuse every time.