If you've not looked into brain concussion, I recommend spending about 15 minutes watching YouTube videos about them. I had always heard about concussions, probably learned what it meant in school at some point, vomited it out on the test, and forgotten most of it, so until recently, all I really knew about a concussion is that it's this bad brain trauma thing that seems serious, but not too serious, and that was about it.
Then I got one.
Except, the CAT scan said I was fine (and this is normal! But I didn't know that), so I didn't think anything of it. When I started experiencing the symptoms without having any idea what it was, however, it was quite scary. So, if you're like me and never learned about them, take five to fifteen minutes to watch a YouTube video or two on what concussions are. If you ever get one, you'll be glad you did.