It's true that nearly every guy can fight a little bit naturally, without having anyone show him the right way.
It's true also that the average boy or man might sit down at a piano and be able to pick out some sort of tune with one finger; or he might use the "hunt and peck" system on a typewriter until he had written a couple of lines; or he might jump into a pool and swim a bit with the dog-paddle or with his version of the breast stroke.
But he never could become a good pianist without being taught to play correctly. He never could become a fast, accurate typist without being drilled in the touch system. And he never could become a speed swimmer without being shown the crawl stroke.
It's no more natural for a beginner to step out and fight correctly than for a novice to step out and skate correctly or dive correctly or dance the tango or do the slalom on skis. Even Babe Ruth and Joe Louis, despite their prowess in other fields, were beginners when they took up golf; and each had to learn to swing a golf club correctly in order to assure accuracy and distance in his drive.
It's strange but true that certain fundamental movements seem unnatural to the beginner in nearly every activity requiring close coordination between body and mind.
Fist-fighting is no exception. Some of the fundamental moves seem awkwardly unnatural when first tried. That's particularly true of the movements in explosive long-range straight punching, the basic weapon in fist-fighting or boxing.
In fighting, as in many other activities, it's natural for the beginner to do the wrong thing. It's natural for him to swing rather than punch straight. It's natural for him to hit with the wrong knuckles of his fist. It's natural for him to use leg-tangling footwork, etc.