Final answer:
Retrograde amnesia is a type of amnesia where a person is unable to remember events or information that occurred prior to a brain injury or trauma.
Step-by-step explanation:
Retrograde amnesia is a type of amnesia where a person is unable to remember events or information that occurred prior to a brain injury or trauma. This means that they may have difficulty recalling their past and may not recognize people or experiences from their life before the injury. The extent of the memory loss can vary from person to person. For example, former NFL player Scott Bolzan suffered a head injury and lost 46 years of his life's memories instantly.