Sometimes I get a type of headache that feels like a build up of pressure in a specific place in my head, and it feels like if I just drilled a small hole in that place then it would let all the excess air out with a hissing sound and the headache would be gone.
Anyway, I think that's probably where the evidence of ancient trepanning comes from. Less a treatment sugeested by an early 'doctor' and more someone going up to a friend or relative with a sharp object, pointing at their own head and saying "Could you quickly help me with something?"

The world is such a place that if someone else reads this then there is a non-zero chance that their response would not be "Well that would be a bad idea" and instead would be "Do it yourself, you coward!" And I find that a strangely beautiful thing.