Retrograde amnesia is usually caused by head injury, cerebrovascular accident, stroke, tumor, encephalitis, chronic alcoholism or brain damage to parts of the brain besides the hippo campus. People suffering from retrograde amnesia are more likely to remember general knowledge rather than specifics.
Retrograde amnesia is usually temporary and can be easily recovered by exposing the patient to memories from the past.
Also, no coach has the right to ban you from doing something. It's not their job to tell you so, but I understand that he is only looking out for the team's best interests at heart.
