“Over time, as the self-serving distortions of memory kick in and we forget or misremember past events, we may come to believe our own lies, little by little. We know we did something wrong, but gradually we begin to think it wasn’t all our fault, and after all, the situation was complex. We start underestimating our own responsibility, whittling away at it until it is a mere shadow of its former hulking self. Before long, we have persuaded ourselves to believe privately what we said publicly.”