One would know about oneself. The ritual of mila is very central to our identities as Jews. It is the sign of our covenant. It is not mutilation and it is not statistically harmful. Would you also impose your values on Maasai, Fulani, Lahu, and Mursi?
If the Maasai moved to a Western country and performed scarring procedures on their infant child, they would be arrested. Incidentally, circumcision creates a scar around the circumference of the penis, but is not held to the same standard.