Here is why: they can't tell you that they don't know or that they are dumb, because of the title they hold—teacher, admin, president, etc. Their title implies merit, so they lie. Did you ever notice it? When I did, I started to get pissed off, darlings. 🐾
Extra: Of course, this is not true for every authority figure, but most. It's easy to lie, and their position usually allows to punish anyone that questions them. 🐾