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

Once upon a time, this idea of having a trained, disciplined, cultivated memory was not nearly so alien as it would seem to us to be today.

It is forgetting, not remembering, that is the essence of what makes us human. To make sense of the world, we must filter it. "To think," Borges writes, "is to forget.

I have never been particularly good with languages. Despite a dozen years of Hebrew school and a lifetime of praying in the language, I'm ashamed to admit that I still can't read an Israeli newspaper. Besides English, the only language I speak with any degree of fluency is Spanish.

Just as we accumulate memories of facts by integrating them into a network, we accumulate life experiences by integrating them into a web of other chronological memories. The denser the web, the denser the experience of time.

Languages are something of a mess. They evolve over centuries through an unplanned, democratic process that leaves them teeming with irregularities, quirks, and words like 'knight.'

I met with amnesiacs and savants, educators and scientists, to try to understand what memory is, why it works, why it sometimes doesn't, and what its potential might be.