You know how I can tell whether people "get it" or not. By what they do after receiving Communion. Some walk right out. They "chew" and "screw", so to speak. How rude!
What if guests did that in your home?
Then there are those people who stay to receive the priest's final blessing and then leave. The choir is still singing. They're singing for the congregation and the people they're singing to aren't there. How rude! The congregation should be participating anyway and singing too.
Lastly, what ever happened to praying a thanksgiving to God. It doesn't take long to say "thank you."
People just don't "get it."