...at the point where the illusion becomes too expensive to maintain, they will just take down the scenery, they will pull back the curtains, they will move the tables and chairs out of the way and you will see the brick wall at the back of the theater.
- Frank Zappa
Ignorance and stupidity are not synonymous, but they can go hand in hand. See, everyone is ignorant when they're young, but the stupid ones can take that shit to their graves.
One of the biggest signs of wisdom is acknowledgement of your own ignorance. And one of the strongest indicators of ignorance is proclaiming your wisdom. I have no idea if that's true, but that's what I've heard.
No longer trending rules like "take your hat off at the table" (actually in the house) were there for early identification of pieces of shit. You wanted to know the second someone crossed your doorway whether they were ignorant or wise, rude or respectful.