Mark makes some very good points. Insofar as we are all more susceptible to future injuries, none of us will ever fully recover. That means that we will most likely have to make some permanent lifestyle changes--particularly with regard to avoiding risky situations in which we could sustain further head trauma.

I think, additionally, that exposure to light and noise, as well as physical and mental exertion generally, should also be considered "risky" situations for us--even if our symptoms have diminished. Overstimulation and overexertion can lead to terrible relapses of symptoms, even if you've been symptom free for awhile. Such relapses can happen quite suddenly, and with very little warning. This happened to me.

So I agree with Mark that in at least that sense, we should look at our injuries as permanent, even if our symptoms improve over time.