I learned the hard way that concussions can have major impacts in your mental functioning. I've had a few concussions over the years from various wreckless activities and never considered them a big deal as I could always shake them off in a day or three. But the last one I had after getting rear-ended and suffering minor whiplash, which had the lowest physical impact of all of my concussions, absolutely wrecked me and had a huge impact on my work (and personal life). Impacted mental processing, memory, emotional regulation, light sensitivity, focus, etc. At the time I was working as a lawyer in a big firm and keeping up with the workload nearly killed me. A friend of mine from law school went through similar issues after a car accident.

It took my friend a few months to get better, but it took me about two years. I'm doing OK now, but that's only with the help of medications and coping mechanisms. My doctors tell me that concussions are unpredictable and this could have happened from any of them. They also say I'll likely never get back to the level I was before the accident.

My experience is probably an outlier, but people should know how badly concussions can impact you long-term. The blowback in this thread to calling it a brain injury tells me that people don't realize how serious concussions can be. They are in fact (minor) traumatic brain injuries, and any injury to the brain is scary. If you want to be scared straight, check out all of the desperate cries for help in r/TBI. I was lucky compared to many of those people.