Ninety-nine percent of the people in the world are fools and the rest of us are in great danger of contagion.

The line is a sardonic, hyperbolic complaint about the prevalence of folly and the ease with which it spreads. By framing foolishness as “contagion,” it suggests that stupidity is not merely an individual failing but a social force: people absorb habits of thought from their surroundings, and even those who consider themselves sensible are vulnerable. The joke also contains a self-undermining edge—“the rest of us” implies a small elect of the wise, yet the fear of infection hints that no one’s judgment is secure. Read this way, the remark critiques intellectual complacency and urges vigilance about one’s influences and assumptions.