Streetfighting vs martial arts. do you really need martial arts?

I was watching a anime called kenichi the strongest disciple and there was this guy called berserker that didnt know martial arts but could still mop the floor with martial artist. So I was wondering do you really need to learn a martial when were actually all born with a martial art inside of us(albeit an unrefined one). If you take basics from some arts and fight day in and day out for a year you should be able to take someone that did karate for about a year right?theoretically?right?