system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:As a kid - when you jumped from a high spot and your feet stung the first time, but not subsequent times?

As a little kid competing to see how high we could launch ourselves from the swings, it was commonly known that your first landing would make your feet sting like hell, aka 'busting our capillaries', but after that it would feel like normal. What, if anything, was actually going on?
gpt
Your brain recognised the impact as non damaging, and so when the signal comes in the next time, the brain essentially sets your nerves to ignore it, so that you don't undergo unnecessary discomfort (it's a lot more complicated, but this is a simplification). This is largely caused by your own confidence in your safety, as it knows from experience that you have been safe previous times. But the setting to ignore it only lasts a couple of hours, as the brain takes it off to avoid mistaking actual injury for another non-injuring impact.