Boys will be boys .. what does that mean exactly?

My son is a boy evidently, my friend's son is a boy, evidently.. since when did that mean that boys do these things to other boys in quite this vicious, random, potentially fatally, pack/ gang-led way?

Yes, we may have had Mods and Rockers on the very same seafront several decades knocking hell out of each other - but everyone who was in those ruckuses knew what they were in for .. the predatory gangs of kids these days are a frightening crime phenomenon .. in London 14-15 year olds are using guns and knives without compunction (not even to 'look big') but because that is what they 'do' ... a quote from a 22 year old ex-teenage gang member said they scared even him - as they carried knives for protection but the way kids are using them these days is de-sensitised, senseless, callous, remorseless and pschopathically devoid of comprehension. There is a real 'sick' generation of kids growing up and we ignore this at our peril.