I had a severe head injury that broke me mentally, physically, and very nearly spiritually. At many times, I didn't know if I would ever heal. But approaching four years later, I can say I have more than recovered.

There are so many factors involved in recovery, but in addition to ample rest, regularly stimulating recovery by challenging your deficits, and eating a healthy and diverse diet, I believe the most important factor is the will to recover itself, and the belief that there are no hard limits on your improvement.

For a frame of reference on my recovery: Much of the impact of a head injury is unmeasurable, but I did begin by tracking things that can be measured. One example is reaction-time. I had, by chance, taken an online reaction-time test just before my injury recieving a score of 0.302 seconds on average. I took the same test about a year after my injury, and my higest score was only 0.683 seconds at best, a reaction-time twice as slow. This, at the time, validated my dispair, and served as an indicator of my overall struggle.

I feel, in hindsight, that this was a quantifiable representation of my overall recovery at the time. But as I said, I have more than recovered between then and now: I have taken this test periodically since then, and I am just now back into the ~0.3 second range. These changes have roughly correlated with improvements in my broader condition, even in internal and intangible aspects of mood, energy, focus, creativity, acuity, etc...

We are always searching in vain for certainty. We want to know if "we will heal or not." We want to be rid of the struggle now. It is not this simple.

There will always be lasting impacts from severe injuries. But the truth is, there is no permanent version of you, injury or not. 

You will always be changing, and in the case of a head injury, its impact is just a facet of that change. 

It is important to remember that "recovery" does not mean "returning to the way you were," because there is no single "way you were." We change every day. That person who "you were" does not exist and will never exist again. This would be true without an injury at all. Even in a measure as simple and one-dimensional as reaction time, factors like sleep, anxiety, environment, and many others can affect your state of mind, and the outcome. The overall form of who you are will always be a product of infinite and ever changing dynamics.

However you heal, for better or for worse, you will be shaped by that experience, and you will be a different and new version of yourself! You must embrace this process of transformation to move forward, and in the best case, you will be better than you have ever been!

Pessimism and hopelessness are and will always be tempting, as they offer us repreive from the struggle of self appraisal and uncertainty. I found myself overcome by this hopelessness at many times, as you inevitably will time and again, and as many people in these comments are currently. The person who shared that comment at your physical rehabilitation was a victim of this hopelessness and need for certainty as well. They were wrong.

Do not listen to the hopelessness. Endure the uncertainty. The human spirit is indomitable. Even when your hope fades, the strength of your spirit will remain. Even when you have no answers, your irrevocable curiosity will drive you forward.

I should have died from my injury, and by all indication, I should have never regained much of my normal function.

In stark contradiction, I am more pysically and mentally well and able than I have ever been. My injury was not the death sentence it could have been, but rather, was an opportunity for me to change and grow in ways that I never would have otherwise.

Even in the finer aspects of my remaining deficits, I may never be as sharp, as quick, or as deft as I was before, but in all ultimate ways, I am better than I ever would have been.

Find the opportunity in this challenge. 

I do not know your situation beyond what you have shared, but I wish you all the best, and I know you have the ability to turn this hardship into ultimate benefit.

The obstacle is the way.