Yeah... my wife worked in a head trauma long-term care facility for a couple of years after she graduated from college. A brain injury can change who you are, not just what you remember... And the worst part is, she said that many of these folks remember who they used to be, and are upset that they can't be that way again.
I am one of those idiots who used to think that helmets were over hyped, uncomfortable, and too hot to wear. That all changed one fateful day when I was in a motorcycle accident. I was in a coma for 5 days. The doctor nearly drilled a hole on my skull to relieve the pressure inside my skull from fluid buildup and swelling.
It changed me, big time. For the first year I had great difficulty carrying on a conversation. I could not remember how to sound out words, even though I had spoken them a few minutes before. I would forget what the conversation was about while speaking in mid sentence.
I read memory improving books and played table games that relied on memory skills.
I did what I could to get back to what I used to be like.
I used to have photogenic memory. I could read a book and months later someone could ask me a page number and I could recite it darned near word for word. I could take apart a blender, sewing machine, ect., walk away from it for a few weeks, and remember exactly how it came apart and how it went back together.
My memory is nowhere like that now.
Now, if I am working on particularly complicated things, I have to write notes to myself, draw sketches or take pictures of components before and during disassembly to ensure I reassemble things correctly.
I lost friends. They told me I am not the same person now that I was before.
To myself, my personality has not changed, but that's just my interpretation I guess.
I remember how it was, and I know why it changed.
Please wear a DOT approved helmet.
Not wearing one may not kill you, but I know for darned sure that it can change you in ways you never thought of until it happens to you.