The Spark – Bob Simon reports from Tunisia, where protests against the repressive government not only toppled its autocratic ruler, but sparked the uprising in Egypt that forced President Hosni Mubarak to resign. Endless Memory – Lesley Stahl reports on the recently discovered phenomenon of “superior autobiographical memory,” the ability to recall nearly every day of one’s life. Stahl interviews the handful of individuals known to possess the skill, which scientists are only now beginning to study.