The punch that is seen can be dealt with via rolling with the shot in order to take some of the mustard off it , that can be learned thru training. Also techniques to strengthen the neck can help absorb some of the power of a punch, the knock - out aside from piss poor conditioning ( running out of gas if you will ) often comes the brain twisting on its stem causing a short circuit of the neurological system. So the stronger the neck the better chance you will be able to absorb the punch. However everyone is wired different. I know this one guy can take the best str8 punch in the world, but you touch him on the side of the head and he is an instant Muppet. Everyone’s a little different, Genetics plays a role here . I have found that long necked fighters tend to have more of the Turkey neck effect, and thus get canvassed a bit more when hit cleanly

Emotionally & Physically I think it goes to individual person to person.. Hunger, and determination is something that has to come from within. A good trainer can help try and spark that flame. Try and fuel that fire. But ultimately a fighter has to want it.