Dr. Eric Kandel in Science of Us

A few weeks ago, my boyfriend forgot the PIN to his debit card. A little weird, we agreed, but probably only temporary; sometimes, you just blank on things like that. But it's now been nearly a month, and the memory of his PIN simply never came back. I was curious: How could such a familiar string of digits, one that he’d successfully stored and retrieved in his memory over and over for more than a decade, suddenly — and apparently permanently — disappear?
Read more: http://nymag.com/scienceofus/2015/01/can-your-brain-delete-something-lik...