According to the story told by OJ and his family, he didn't even know what his initial stood for until the 3rd grade when his teacher read out his full name. He was called OJ from birth. He didn't know the O stood for Orenthal.

Stars are likely assigned identities. Their birth dates may not always be their real birth dates.

I think it was u/lonewulf who once mentioned to me how every time a royal gives birth they leave the hospital looking just perfect. Kate Middleton supposedly just gave birth but looks great as she leaves. Mostly likely it's just a show. The kid was born two or three weeks earlier, but they "leave" the hospital on a chosen day for the public to see.

Intelligence services give people new identities in clandestine operations. Q already hinted how they wanted the public to follow the stars. These people live as dolls. It's the real price of fame and once you're in that world you can't leave "alive".