Originally Posted by soyboy
i'd say unless you're like 10 or younger your skull is pretty well formed and hardened, it could be the skin and muscle getting compressed and leaving a mark, ig it bothers you that much get a new helmet, if it doesn't bother you don't worry about it, if you want advice from someone who isn't an unemployed photographer ask a doctor or nurse
As an engineer, I agree with this photographer's opinion. I doubt it's your bones moving. Bones are pretty hard, and helmets are designed to fail before your bones do (that's the point).