My ‘real’ (original, Dutch-) name is Joop. (Pronounced: Yope_).
One day, in 1956, a friend and I were walking towards the old Sydney Stadium. (_Might have been to watch the Harlem Globetrotters play.) In the street, this friend, Neil, introduced me, to someone as: “Joe”. That was the moment my name was Anglicised.
In the eighties, while changing the last name, from the Dutch: Mul, to the Irish: Mulholland, it was the right time to change, Joe to Jo. At school we were emphasising non-sexism and multiculturism (and the ‘senior’ form of Joop, is Jo -short for: Johannes.)