I got the bill for my surgery. Now I know what those doctors were wearing masks for.

Boren’s quip hinges on a sudden reversal of expectations: surgical masks are ostensibly worn for hygiene and patient safety, but the speaker jokingly reinterprets them as a way for doctors to hide their identities after charging an exorbitant fee. The humor comes from treating the medical bill as a kind of “crime scene,” implying sticker shock so severe it feels like being robbed. As social commentary, it taps into long-running anxieties about the cost of medical care and the opacity of billing, using a one-liner to express distrust of institutions that are otherwise associated with care and professionalism.