When I make a big save on the motorcycle, that always leaves a mark and gives me an afterglow. Mix of adrenaline peak and then its descent, relief, being proud of yourself because Nature and Physics were about to end on top and screwing you real bad, but your reflexes turned the storyline around.
The brain knows that had you not made the save you'd have a good chance of ending up in a hospital bed, significant chance of becoming paralyzed, and non-zero chance of dying on the road like a dog.
The days after are really great, everything is much better. The food tastes better, the sky is bluer, the water is more refreshing etc.
Humans, especially men are made to go out in the wild and put their bodies on the line to face Nature and all the elements that she throws back at them.
When you put your body on the line and you make it back after defeating the elements, that's a feeling that is superior to drugs