Something i just thought about, if humanity found aliens or whatever they would probably be horrified at human headbutting other things. Like thats their most important organ in an already vulnerable part of their body (no shell, no extra protection, not regressed into their body) and their using it to fight of all things. Lets say a person gets into a fight, maybe on an alien planet or a ship or whatever and the human and whatever are fighting, maybe an alien or another human, theyve only been punching and grappling, they grab the thing solidly and absolutely slam their forehead into their opponent before someone could break it up. Now picture this, the other aliens are horrified cus the human just effectively put itself in the most risk it could, and it does it AGAIN, and another time until they manage to break it up (after the human definately broke some kind of facial feature of their opponent) and tells them thats just a pretty common move humans use in fights
You forget how formidable the humble skull actually is.
