A person’s memory is a sea of images and other sensory impressions, facts and meanings, echoes of past feelings, and ingrained codes for how to behave—a diverse well of information.

But surfers, of all people ... s memory is wildly unreliable. It typically takes us getting about three steps from the water’s edge to forget the size and critical nature of that last ride.

It is a record of experience that guides future action. Memory encompasses the facts and experiential details that people consciously call to mind as well as ingrained knowledge that surface ...