system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do you always get a distinct feeling/smell/ thing when you get struck in the nose or face?
gpt
I don't think the exact cause is known, but shocks to the brain - which could come through a blow to your face - can produce these odd (metallic?) taste sensations. They're common in concussions. Presumably a taste center in the brain is being knocked and playing up. You should get any potential concussion checked out in case there's a serious injury.