The phrase "fearful event" means something that is scary or frightening. It refers to an occurrence or situation that causes fear or anxiety. Full definition
«Removing the grid - cell network removes memory for places but leaves completely intact a whole host of other important memory abilities like recognition memory and memory of fearful events.» (sciencedaily.com)
A mouse's memory of a single fearful event is one thing; the complex associations of human memory, powered by a dense network of neuronal connections, is quite another. (discovermagazine.com)
In more mature persons, however, memories of fearful events are put in perspective, and people generally do not feel the same fear they felt as a child when confronting a similar situation as an adult. (psychology.jrank.org)