You can certainly disagree and have a different opinion. And yes, adrenaline plays a role (though both people in this equation would have an adrenaline rush), but to be clear: this is something I've used far after high school and on people who were bigger than me. Things I've taught other people for self-defense as well as my little sister who is not large or built to overpower people and she has had success before. You don't "bend muscle", they'll overpower you. That was the original point. I'm talking about joint and anatomical weaknesses that everyone has. Targeting someone's eyes, smashing your head into their nose, a sharp hit to the throat or open palm strike to the nose, inward step on the side of their knee, elbow strikes to the face, neck, or diaphragm... these are not "hypothetical body parts" but actual things that are taught to people learning self-defense as well as people in the military. Brazilian Jiu-Jitsu, Krav Maga, and even a straight forward self-defense course can often discuss these things including "force multipliers" which is anything to increase your force and level of threat like keys as a slashing weapon or in your knuckles if you hit.