I think it very much depends on the personality.
A coworker almost killed themselves choking on food recently (felt the blockage, and left the building through a fire exit when the gag reflex started because they didn't want to vomit on the carpet). The door locked behind them and they were all alone when the blockage slipped down and cut off their air supply.
They managed to clear the blockage just as they were losing consciousness, but the close call has been haunting them. Their personality type has them dwelling on what could have been.
It a distinctive difference in personalities who participate in risk taking past times or jobs. They have near misses and close calls regularly, but they don't dwell on them, or even necessarily remember them until someone else reminds them.
If you've had a traumatic event and you're having dreams about it, it's your brain (and subconscious mind) processing the trauma. This sounds cheesy, but as soon as you wake up after one such dream, state out loud "I survived that, and I'm OK".
Your subconscious mind hears and processes everything. It's a very powerful bio-programming technique when you learn how to communicate effectively with your subconscious.