That still doesn't matter. What, you think that every kid that grows up in hard neighborhoods is constantly fighting? That might be true for some people, but even then it doesn't necessarily hold any value in an actual fight. Getting into fights as a kid doesn't mean that you've learned shit about fighting, it just means that you've been in a lot of fights. Those two are not synonymous. What matters is strength, smarts, and above all else technique. I guarantee you that there are a lot of big, bad South and Central American footballers that's seen a lot of really bad shit throughout their childhoods, and they would probably all get their asses absolutely destroyed by Zlatan or by anyone with just little a bit of training behind them. This whole idea that merely growing up in a bad neighborhood automatically makes you the baddest motherfucker in a fight is just a tired idea with no value in real life.