Genetics has a lot to do with who we are, our race/looks, height, thoughts/intelligence even. Yet many cling to the idea that nurture can overcome nature. Our mtDNA and Y chromosome is the hardware our consciousness runs on. Just the way we are, not a strong or a weak thing you say, there are mutations in us, some are beneficial, some are good/bad, but I disagree, of course some are weak or objectively bad. Hotwheels from 8chan made a good post about how he doesn't like his existence and would support euthanasia for people like himself. I doubt anyone would want to be born with tay-sachs, and when you say not strong/weak you may be using a surviorship bias to say it, although most humans are on average quite healthy.
I was originally going to post how I had the opposite reaction to an event like this like you, a car crash when I lost control in the rain, thinking I was about to die. I didn't and I was mostly fine aside from some back pain from whiplash. I have aphatasia, do you happen to have it? I have a bad memory so I don't think people with it can get PTSD, so it is an adaptive mechanism, although I lose a lot of richness in thought I suppose I have been through really bad things with no problems, had a gun pointed at me, demanded my stuff, and I said no, he was confused and didn't really know what to do, I left. I didn't really think much of it but others thought it was crazy. No PTSD either.