Memory can be tricky. We assume that we'll remember much more than we actually do. Then we run up against a moment of struggle, failing to pinpoint specific details of an event we've experienced, and we wonder how much of our lives we are fully taking in.

You might make a mistake because something you know doesn't surface in the moment you need it; you have a frustrating, fuzzy sense of I should know that. Why does our ability to "record" sometimes fail us, and what can we do about it?