The appropriate time, that is, for him. Having turned over his mental life to a computerized system, he refuses to be pushed around by random inputs and requests. Naturally, this can be annoying to people whose messages tend to sift to the bottom. "After four months," Biedalak says sadly, "you sometimes get a reply to some sentence in an email that has been scrambled in his incremental reading process." Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm