Truly and genuinely stupid people.
I agree about the elders and their "respect". I can say completely honestly that I am a very polite, respectful, and personable kid. But, if you're an a-hole, that can go away very quickly. I totally understand that I'm 18, have basically zero real life experience, and in fact, rarely "know better" than anyone that is to be considered an elder. I get it. I'm a young, oblivious to the real world kid, but I'll be darned if you're going to write me off as a moron because of my age.
Teens that think "they hard", or, in other words, are badasses. You're not. You're an arrogant, ignorant turd that is going to be apalled when reality hits and you are dumped in to life. Just because daddy bought you a new car, you speak like you're intentionally butchering the English language, and have an incredibly heightened sense of your masculinity when you're around your friends does not mean you could whoop me, take me, beat I disagree, etc.
Genuinely stupid people that somehow become TEACHERS. You all would be blown away with how much time is wasted during a school day. Of the six hours, we do maybe an hours worth of work.
Young adults who have no respect for others.
When someone is rude to my mother. Make fun of my bro or my dad all you want, but mess with my mom and Imma mess up yo face!