Your face is thoroughly punchable. No offense or anything. It used to be thought that the tough bone structure of the distinctive flat human face was all to do with increasing bite strength, helping us tackle hard food like nuts and seeds. This seems unlikely, however, as recent archaeological evidence suggests that our ancestors lived on a mainly fruit-based diet. Now scientists at the University of Utah think that it's actually more likely to be a kind of defensive armouring that helps us withstand being punched in the face. Australopithecus, our distant hominid ancestor, walked on two legs and, as such, had two hands freed up for a good bit of fisticuffs. As a response to this, the parts of the face that get injured the most when punched, such as the jaw, cheekbones and the orbits of the eyes, became thicker and stronger over time. Further to this, male faces, with their pronounced jaws and brows, show much stronger adaptation to being punched than female faces, indicating that the males did much more of the fighting, whilst the female Australopithecus presumably stood between them shouting "leave him, Steve, he's not worth it!".
