Red hair, sir, in my opinion, is dangerous.

The line is a compact example of Wodehouse’s comic method: an absurdly categorical pronouncement delivered with mock gravity (“sir, in my opinion”). By treating a trivial physical trait as a serious hazard, the speaker reveals more about his own prejudices and superstitions than about red-haired people. The humor comes from the mismatch between tone and subject, and from the way Wodehouse’s characters often elevate petty social “rules” into solemn principles. Read more broadly, it satirizes snap judgments and the human tendency to rationalize irrational dislikes as if they were reasoned conclusions.