What is the purpose of etiquette and why does it matter that we use certain words more often than others, act in certain ways instead of others, and so on? How do we take charge of our relationships on and off the mat towards the ultimate goal of daily Aikido training: Masagatsu Agatsu.
Belief Influences Behavior.
Everyone is familiar with this pop psychology reference. It's a pretty obvious idea that we all behave in ways that reflect our beliefs. Behaviors of course mean anything we take past the thought of it including actions, words, gestures, etc...
In Aikido, traveling from dojo to dojo, one might come to realize that there are so many variations on etiquette, and of course, the repercussions associated with making a mistake. It would be an easy thing to decide that one person's approach is the right or wrong one, but in reality, it is the underlying current of the purpose of etiquette that matters most: mutual respect.
For example (we can stick with Japan since Aikido is a traditional Japanese martial art): in Japan we have a number of suffixes that are often added to a person's name when speaking to or about them.
Kun or Chan: often denotes extreme familiarity, often someone your own age that you are friends with, even romantically.