Aaron Sorkin has said of screenwriting, “The worst crime you can commit is telling the audience something they already know.”
I agree, as regards storytelling – in film, in music, in art. For teachers, though, it’s just the opposite.
The worst crime a teacher can commit is leaving a topic before all the students understand.
It takes time for students to digest a topic. Moving on before they truly comprehend leaves confusion, self-doubt, and a lack of subject mastery. Do this enough times, and students become convinced they are incapable of learning.
Repeat, repeat, repeat – and help individually until every student understands.