In my day job, my team lead is a decade younger than me. Whet he brings to the team is the ability to organize stuff, as well as technical excellence. So I have tremendous respect for him. Same with photography teachers - when I teach, some of my students are high school or college age. Some of them are my age, and some of them are retirees with 20+ years on me. They're choosing to take my class because I have something to share that they want to learn. And when I take classes from others, it's because they are sharing something I want to learn. I've learned the etiquette of keeping my mouth shut in class when I think I know better than the teacher, as a courtesy to them - I'm not the one getting paid, they are. Now, if they spout off something that's factually WRONG, I'll speak up. But I don't try to override them because I know how obnoxious it is to have a student try to take over my class.