Answer:
This is an example of Post-traumatic amnesia
Step-by-step explanation:
Post-traumatic amnesia is the an experience of confusion that an individual would experience after a fatal and deadly head injury. This is usually a traumatic experience for an individual and might lead to a permenent amnesia if nothing is done towards the injury.
For Gill not to remember any of his friends he made while recovering from the brain injury he sustained in the Gulf war showed that he is suffering from the Post-Traumatic Amnesia which happens to be as a result of his head injury.