Mind
Explanation
The Joke
The comic traces the evolutionary development of the human brain's capacity for imaginary arguments. It begins with the observation that as the neocortex grew larger over evolutionary time, humans gained the ability to have increasingly elaborate imaginary arguments. In the modern era, the brain's internal monologue has essentially replaced functional reasoning — people spend their mental energy rehearsing confrontations and winning debates that will never happen, rather than doing anything productive.
The comic notes that at some point the brain's "arguing simulator" completely replaced its "internal reasoning" function. One character accuses another of yelling at a "conventionally attractive movie star" in their head, which "proves acting is just an illusion" — the arguments have become so disconnected from reality that they don't even make sense. The final panel observes that the brain's debate-rehearsal function "serves no known purpose" for functioning adults, likening it to a vestigial organ.
The Humor
The comic takes the universal human experience of rehearsing arguments in the shower or while driving and reframes it as an evolutionary adaptation that has outlived its usefulness. The humor comes from the escalation: it's not just that we occasionally imagine telling off our boss — it's that this function has completely taken over the brain, crowding out useful thought entirely.
The specific detail about arguing with conventionally attractive movie stars adds absurdist humor, acknowledging that our imaginary arguments aren't even with real antagonists but with fictional idealized opponents. The comparison to a vestigial organ (like the appendix) is the final comic twist — our most active mental process is, from a survival standpoint, completely useless.
Broader Context
SMBC frequently examines human cognition and its evolutionary origins, often arriving at the uncomfortable conclusion that our brains are poorly optimized for modern life. This comic fits into Weinersmith's recurring theme of humans as sophisticated biological machines running outdated software — we have the hardware for abstract thought, but we mostly use it to win arguments against people who aren't there.