Of course, but there are always going to be moments of friction, where some amount of "un-niceness" or even anger is at the very least understandable, if not ju

Of course, but there are always going to be moments of friction, where some amount of "un-niceness" or even anger is at the very least understandable, if not justified. Plus there's a difference between "be nice" and "go the extra effort to be nice". You can be perfectly friendly and nice and you can strike up some chit-chat and develop a low-key "relationship" with someone.