Jargon often hides how simple an underlying mechanism actually is

Munroe's central device throughout the book is restricting himself to the one thousand most commonly used English words, banning technical terms entirely, which forces him to describe machines and natural phenomena purely in terms of what they do and how their parts interact. A nuclear reactor becomes a "machine that uses hot metal to make water hot, so the water can make wheels turn to make lightning that goes to houses."

This constraint isn't just a gimmick; Munroe treats it as a genuine test of understanding, since accurately describing something without relying on its specialized vocabulary requires actually grasping the underlying mechanism rather than simply memorizing its name. Where the plain-language description becomes awkward or impossibly long, that awkwardness itself reveals genuine complexity; where it flows easily, it suggests the "complicated" name was disguising something fairly simple all along.

Munroe uses this repeatedly to puncture the mystique surrounding technical fields, showing that much of what sounds intimidating is describable in ordinary terms once someone takes the trouble to try. Takeaway: if you can't explain something without jargon, you may not understand it as well as the jargon suggests.