Sometimes we flag the obviousness of what we’re about to say to avoid seeming condescending or clueless. In January 2021, facing criticism over the COVID-19 vaccine rollout, Dr. Anthony Fauci said in an interview on the Today show, “Obviously, we have to do better than that.” He stated that he was stating the obvious—because not doing so would make him appear out of touch with public opinion.

Sometimes, though, using the codicil “obvious” is meant to shame the listener: You haven’t read the memo, you are deficient in common sense. Indeed, the shame attached to missing the obvious—or to stating what is obvious while under the impression that it is not—runs deep. Nothing is worse than offering a brilliant suggestion, only to realize that many heads have already nodded it...