I recently argued with my 7 year old that there are some things you are just required to know... because I said so. I rarely bust that out! But on that list were:

Swimming for survival not leisure
Riding a bike
Tying your own shoes

I'd like to add to the list- being able to both give and receive constructive criticism, how to ask a thoughtful, intriguing question and how to respond to one, how to make polite conversation even when the party is boring and how the magical, mystical internet really works!

I also think everyone should be required to know (really know, not have read about someone in a book) who is smarter than they are.