Growing up in the days when you still had to punch buttons to make a telephone call, I could recall the numbers of all my close friends and family. Today, I'm not sure if I know more than four phone numbers by heart. And that's probably more than most.

A meaningful relationship between two people cannot sustain itself only in the present tense.

The way to get better at a skill is to force yourself to practice just beyond your limits.

With our blogs and tweets, digital cameras, and unlimited-gigabyte e-mail archives, participation in the online culture now means creating a trail of always present, ever searchable, unforgetting external memories that only grows as one ages.

'Moonwalking with Einstein' refers to a memory device I used when I memorized a deck of playing cards at the U.S. Memory Championship. When I competed in 2006, I set a new U.S. record by memorizing a deck of cards in one minute and 40 seconds. That record has since fallen.

The fact that books today are mostly a string of words makes it easier to forget the text. With the impact of the iPad and the future of the book being up for re-imagination, I wonder whether we'll rediscover the importance of making texts richer visually.

Our culture is an edifice built of externalized memories.