LA CROSSE, Wisconsin (CNN) -- Give Brad Williams a date, and he can usually tell you not only what he was doing but what world events happened that day. He can do this for almost every day of his life.

Williams is one of only three people in the world identified with this off-the-charts autobiographical memory, according to researchers at the University of California-Irvine who gave the condition its name: hyperthymestic syndrome, from the Greek words for excessive (hyper) and remembering (thymesis).

Unlike most people whose memories fade with time, much of Williams' life is etched indelibly in his mind.  Read More...