Why are some people so stupid!?

You shouldn't judge the people why they don't know simple things, and should not use the word "so stupid". Perhaps you get mad because you either have to tell them or show them in your own way. As now there way to do this is same way Ask, share, your best knowledge as calmly you can be it take practice to control yourself. People know things, as other doesn't know to share the knowledge to share the best you can without names calling, losing control of yourself.