Quick, name a famous know-it-all. Depending on your age, Homer Simpson, Hermione Granger, Spock, or the mailman from “Cheers” might have crossed your mind. As TV tropes and psychologists suggest, a know-it-all is someone who shuts down new information from others and leans into preconceived ideas. It is hard for him or her to adapt to new ways of doing things. And teachers are not immune to the know-it-all syndrome. We often double down against changes in approach because we want to appear as though we have everything under control. We might even know what we are doing is ineffective.