Many people feel they must multi-task because everybody else is multitasking, but this is partly because they are all interrupting each other so much.

Be able to correctly pronounce the words you would like to speak and have excellent spoken grammar.

Have enough sense to know, ahead of time, when your skills will not extend to wallpapering.

The magnitude of an action may change not only the strength of its impact, but the direction. If you became a dentist, for example, you would certainly be an asset to our society. But what if everyone became a dentist? Who would bake the bread? Who would build the houses?

Know the names of past and current artists who are most famous for playing their instruments.

Be able to live alone, even if you don't want to and think you will never find it necessary.

Spending waiting moments doing crossword puzzles or reading a book you brought yourself.