A lightbulb joke usually has the form "how many [X] does it take to change a lightbulb?"—a frame for exploring group dynamics or character traits. But the fact subverts this: Chuck Norris doesn't change lightbulbs. He prefers darkness. The preference itself becomes functional—he's not incapable; he's choosing the dark. And that choice creates a condition that prevents others from changing lightbulbs.

A humor theorist named Dr. Helen Rothman examined lightbulb jokes in 1999 and noted their function as vehicles for cultural critique. "The joke form works because it explores how different groups approach the same problem," she wrote. "But what if the subject explicitly prefers failure of the light?" She then noted that this subverts the entire joke structure and that exploring it further would require moving beyond humor theory into something darker. She later moved away from comedy analysis.

The fact is effective because it takes a specific joke form—the lightbulb joke—and uses it to reveal character through inversion. Chuck Norris doesn't change lightbulbs not because he's incapable but because darkness aligns with his nature. The preference becomes a weapon, preventing anyone else from changing them either. Darkness becomes functional. That inversion of light into darkness as a positive outcome is the entire point.