By the time you get a job, you know how to behave in a meeting or how to write a simple memo.

By the time you know what to do, you're too old to do it.

I knew how to swim by the time I turned 4.

Attention is the fundamental instrument we use for learning, thinking, communicating, deciding, yet neither parents nor schools spend any time helping young people learn how to manage information streams and control the ways they deploy their attention.

Mindfulness means being aware of how you're deploying your attention and making decisions about it, and not letting the tweet or the buzzing of your BlackBerry call your attention.

As for Twitter, I've found that you have to learn how to make it add value rather than subtract hours from one's day. Certainly, it affords narcissism and distraction.