I guess jamiesgirl might feel that if he's not acknowledging his TBI, how is he going to take the necessary steps to promote his recovery? If he assumes he's fine but just has a mild headache and a couple of other minor physical symptoms, then he might do something dumb like seriously overexert himself (as I did two weeks into my recovery, thinking that I was over the worst of it, which I'm pretty sure prolonged my recovery).

Might be easier to hear this tactfully from a doctor though. Denial can be tough to penetrate, even for people without TBIs!