I know this. I used to ride. Got hit by a car swiping three lanes across traffic. They didn't care to look. My head whacked the pavement hard. Got road rash and a concussion. The helmet saved my life though.
Weirdly had PTSD after trying to ride again and dropped it like a bad habit. Helmets save lives, on bicycles too y'all. Just shocking to see how many folks on both motorcycles and bicycles that don't wear a helmet.
You kidding me? Not weird to have PTSD at all. Your conscious brain might have shrugged it off but your body remembers the whole "I could have died" feeling.