She says he sexually assaulted her; he denies it. Is somebody deliberately lying? Not necessarily. Experts say that because of how memory works, it’s possible that both Supreme Court nominee Brett Kavanaugh and Christine Blasey Ford — the woman who says a drunken Kavanaugh pinned her to a bed and groped her at a party when they were teenagers in the early 1980s — believe what they say. And which one of them believes his or her version more strongly is no tipoff to what really happened. “Confidence is not a good guide to whether or not someone is telling...