Yes. Many people who have problems such as poor memory, difficulties in learning and behavioral issues are unaware they are experiencing symptoms resulting from an “unidentified” traumatic brain injury. An unidentified TBI usually stems from a past trauma, and medical treatment was not sought. Sports injuries and physical abuse are two of the more common examples.

See Resources
Unidentified Traumatic Brain Injury (PDF)
TBI Research Review from the New York Traumatic Brain Injury Model System