jamiesgirl,
He is likely just being a guy. Ego, pride, machismo, what ever, feeds this attitude. Add some personality changes and you have a perfect storm of denial.
You need to download the TBI Survival Guide at
www.tbiguide.com. Print it out and highlight those symptoms you recognize.
Why do you feel he needs to admit he had a TBI?
The only thing that matters are how he deals with his symptoms.