system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does jumping/landing/falling "correctly" not give your brain concussions?

Googling this gives stories about people actually getting concussions on trampolines or doing parkour and that's not what the question is.   


The question is, if your brain's the consistency of tofu, how does bouncing around "safely" not just bump your brain a bunch? Why can it survive bouncing on the trampoline or jumping down stairs or sitting in a bumpy car or what we consider "normal" jostling in the modern world?
gpt
Bounces don't give you concussions, your brain has some cushioning and can move around a bit in the head.

what does cause concussions is rapid movements (like whiplash getting hit, or in a car accident) or sudden stops (like falling on the ground and hitting your head hard) that cause your brain to move TOO MUCH and hit/squish up against the skull.

imagine it like a cup of jello. You can toss it around and catch it and the jello has enough give and take to handle it fine. It is when you drop the cup of jello on the ground or it hits a wall that problems happen.