When I was a little girl, my parents spent a good deal of their time teaching my brothers and me how to behave in an acceptable manner in public, and specifically to have good manners towards other people. There were certain rules and regulations that one followed in polite society. Expelling of bodily fluids and noises was to be done in private, "please" and "thank you" were de rigueur, as were good table manners. High on the list of etiquette was never to interrupt a private conversation. E-v-e-r.
Yesterday at the end of the day, a colleague and I were having a conversation about our weekend plans. Both my friend and I like to draw and paint, and we were discussing which media we like to use best, how relaxing it is to utilize the creative part of our brains ~~ just the usual chit-chat and blah-blah-blah. Suddenly a third person barged into the conversation, elbowed me out of the way, and changed the topic completely. Both my friend and I were a bit taken aback by the abruptness of the "buttinski", but I withdrew, and my friend politely engaged in conversation with the intruder. The conversation lasted for quite a while. Afterwards my friend said to me, "That was strange, but I have noticed that happens quite a lot around here. People just barge into conversations and take over..." And it's true, I have noticed it happens more often than not. Have these folks forgotten their manners, or were they never taught?
We have all experienced the awkwardness of being at a party, and trying to include ourselves into groups of conversations. Do we hold back and look like a wall-flower? Or do we walk right up to a group, smile, and start chatting? That first step can be nerve-wracking, and for some folks there is no easy way to do it. But barging into a conversation between two people, elbowing one person out of the way and taking over the conversation with an entirely new subject is just boorish. My mother and father would definitely have a chat with her. "Mind your manners...!"