Arguably what is most surprising about autobiographical recollections is NOT that they are so often false, but that they are so often inaccessible. The vast blanks that most of us have for many hours of our past lives don’t even seem to bother us. Just as we recollect only a few of our nighttime dreams, we recollect only a fraction of our waking moments. We’re blind to them in the same way we are blind to scenes behind our heads. We flow moment by moment down the stream of consciousness, paddling madly through the rapids, leaning back in the calms, sometimes glancing over our shoulders to the past and sometimes peering ahead to the future. But a lot of the journey never gets a second glance. Sometimes a confluence of conditions leads a never-before-recollected past moment to come unbidden to mind (Read & Lindsay, 2000). But a lot of the moments of our lives sink like stones and never again come to light save in the way we ride the currents of our lives (Lindsay & Read, 2006).

Alan and his collaborators did a considerable amount of thoughtful work on meta-cognitions regarding not-known information. He showed that people can often differentiate between details that they saw but cannot bring to mind versus details that they were not shown (e.g., Scoboria, Mazzoni, & Kirsch, 2008). More recently, Krogulska, Skóra, Scoboria, Hanczakowski, and Zawadzka (2020) studied conversation processes through which subjects communicate in their verbal reports differences between unknowns that they believe they never encoded versus those that they believe they encoded but cannot recollect. They also found evidence, akin to Glucksberg and Watkins, that “the more details related to the particular queried information can be retrieved, the higher the feeling that the answer to a given question is known and thus the higher the likelihood that a specific candidate response will be provided instead of a “don’t know” response” (p. 1233).