Bruises of the brain

I read an interesting article about how pretty much everybody has at least some minor trauma, explained as bruises of the brain. Even if it's from things we never think about, they probably still have an effect on how your brain currently works. She wrote a book about that which I'd love to read some time.

But it made me remember a few things that are just things that happened, nothing more than that to me. By thinking a bit more about them now I am wondering what kind of effect they might have on my current life, even if I only know them from stories and not memories.

One of them is that as a toddler I had my finger on a door opening and my mom pulled the door closed, severing my fingertip. I know from the scar on my finger, and my parents explaining how I got it. I was rushed to the hospital but they had to wait still cause a severed fingertip was not gonna quickly kill me apparently, so some cases were more urgent. Then when we finally got some help they got someone to sew the fingertip back on as soon as possible, without any sedation or anesthesia. It's not safe to use on a child that young they were told.
Anyway, I don't remember any of this luckily, but it does make me wonder if this left some sort of bruise on my brain. I do have a bit of a fear of needles, but as long as I don't have to see them I have no problem with like getting vaccinations or stuff.
I have a lot of problems though, the needles thing is just the only one that sounds like it could be related. But brains are weird, maybe a bunch of my anxiety came from this too.