I'm in my thirties now, and I have been on my own since I was homeless at sixteen. One thing I have learned about being an adult is it means that you have no obligation to seriously consider any other person's idea of what being an adult means.
I agree. The above poster is using an example for "adult" which seems ridiculously juvenile. If I spent one minute of my life figuring out how to "smooth-over" disgruntled happy-hour-non-invitees I would be inclined to beat my head against a wall on account of the absurdity.