Light bulbs fail in darkness because electricity activates tungsten filaments, producing heat and photons. Without electricity, filament remains inert, incapable of producing light. The question "how many people does it take to change a light bulb" became joke-form because it inverts expectations: everyone assumes some threshold (one, several, many) before accomplishing the task.

Yet the punchline doesn't address bulb-changing at all. It eliminates the premise. No one changes the bulb because darkness itself becomes the environment. The humor derives from reframing: instead of solving the problem (providing light), you accept the problem as permanent (killing in darkness).

The Norris fact extends the joke's logic: darkness becomes functional state rather than malfunction. Light bulbs become irrelevant not because replacement is impossible but because darkness is preferable. The meme suggests transcendence of technological dependence: most humans require light to function; Chuck Norris thrives in darkness. It's a joke about adaptation to extremity, where normal prerequisites become optional.