Explanations/etymology also appreciated!
For Joe Shmoe, it means a very average or below average person. It’s a derivation of the practice of using “shm-” to dismiss something (eg “Practice shmactice. We’re already perfect”).
And “John Smith” is meant to be the most average name or person imaginable, so they have the “most common” (citation needed) first and last name as well.
In Brazil (Portuguese speaking) we also use Fulano de tal. I didn’t know it was used in other countries!
We also “José Ninguém” and “Maria Ninguém” to mean someone who’s a nobody. It literally means Joseph/Mary (very common names in Brazil) Nobody.
There’s also a name that expresses the same feeling of ‘Joe Schmoe’ in pt-br: ‘Zé Roela’
And to expand on Fulano’s family, we must not forget Beltrano and Ciclano.
And “Zé das Couves” (but this one is used more rarely).