The Zulu aren’t unique in their circumcision minus anaesthetic ritual. The famous blood-drinking Masai are quite fond of the practice too, and even apply it to their female children. Of course, female genital mutilation is another perfectly acceptable practice once the wand of cultural relativism is given a quick wave.
Anyway, Masai men go through a whole battery of initiation rites beside the foreskin thing. Theirs is a warrior culture poised on the knife-edge of extinction, so many of their rituals are designed to weed out weaklings. One of the most extreme examples of this is lion-hunting. Though it’s no longer a common practice, mostly for reasons of wildlife conservation, Masai men were only considered true warriors once they brought down a lion using only a spear and shield.
You may remember thinking the bit from 300 when Leonidas takes down a wolf was prettybadass. Now, imagine a culture that sends lone warriors after fricking lions as a matter of course. Needless to say, Masai either returned men or not at all.