I give up... You can't tell them if they don't want to hear.

Briefly: I will advise a colleague or a student about how to be more effective, with suitable disclaimers that I might well be wrong. They then defend themselves, in effect ignoring what I said about their behavior, justifying what they did without paying attention to matters of decorum or style. I have in the past tried to get back to them, to make them realize what I was trying to say.

I give up...