You and your roommate are discussing your early childhoods and your first day of preschool. She is frustrated because she cannot remember anything related to that first day. She remembers stories that her parents told her about her first days of school because it was right at the time of the events of 9/11, but she does not actually remember the events herself. You would tell her that the inability to remember significant events before the ages of 4 or 5 is common and refers to a loss of memory.