I think etiquette is dumb. I think if you're cool with a person, you either won't do things that bother them, or stuff can be pointed out and you can readjust your behavior. Having rules on the proper way to act makes unnecessary tension.

I had to take an etiquette class in Catholic school, and the person teaching it seemed like such an uppity bitch. She got super offended because her daughter's friend liked the food she made so much she asked for more. She ended the story by kind of yelling, "you never ask for more!"

She could have been flattered someone liked her food, but she decided to get offended because of some stupid rule she was taught.