Am very glad if the previous posts made you feel better. From what you mention, (CT unremarkable after your accident but life being certainly not unremarkable), I'm guessing that you found interesting/useful the comment about TBI assessment (as in CT scanning) not necessarily matching up with how we feel and function day to day.

I'm just posting back to say emphatically that really is strongly how things are. CT-ing (and MRI scanning, which is more detailed) really is/are often a good predictive guide but it's just one type of investigation of anatomical change to brain structure, presumed to be from the injury that it follows.

As well as anatomical brain structure, important though that is, the brain functions through chemicals and electricity. The three dimensions (inter-related as they are) are what's needed for understanding brains working.

CT-ing (X rays) is used so much because it's inexpensive and fast enough to do. It's because this cheap-rapid technology is available that it gets relied upon.

There are some further electronics which display images of some thinking -- like functional MRI-ing and Positron Emission Tomography (+others) -- but they're ultramega-expensive ways to display visual evidence of neurochemical and electro-physiological activity, and even then, ultimately, they're limited in scope.

Aside from electronics, there's also the whole field of neuropsychological assessment, which is also potentially helpful but still rough-guiding. ...And neuropsychs rely on artificially-devised tests and procedures which are not in real-life situations.

Very much depends on correlations and approximations. That's arguably (just arguably) fair enough, for lack of better means in the foreseeable future, but there's harm potentially in placing all reliance on the (cheap-fast) electronics and on neuropsych, because they're really correlative guessing systems based on pattern-observations ... while on the other hand, real science and real truth come through deeper detail and with scepticism -- and it is unassailable fact that neither CT-ing nor MRI-ing (nor neuropsyh-ing) account for the realities of lives after brain injuries.

... Neurons look like tadpoles. There's the head, nucleus, and then the tail which reaches out to communicate (chemically, electrically) passing on messages/stumuli to neighbouring neurons. In a TBI, the tadpole tails get scrunched, = the tails get stretched, twisted, pulled, broken, so the messages can't get passed on at all or get garbled or get passed on indistinctly or only by long-distance relay. However, those tadpole tails being mangled doesn't show up on CT-scanning and may not be apparent on MRIs unless it's a high-power MRI machine, + concentrated area of tadpole-tail mangling, + well-interpreted MRI image.

Keep the faith! ... No, I'm not being religious, but you gotta rely on how you know you feel, not just being told that mere CT-ing shows that you're fine. There are completely mainstream scientific papers and high-level experts in the field who are unanimous about CT-scannng being very fallible and one-dimensional for structure only, and not detailed.

Mind yourself well, (and try to get others positively, cheerfully, helpfully involved too!).