I’M GLAD YOU ASKED!
originally, “Zur-En-Arrh” was just some Silver Age space nonsense. But in “Batman R.I.P.,” Grant Morrison retconned it to be Bruce Wayne’s subconscious reconfiguring of his father’s final words; that in “real life,” Gotham would put someone like “Zorro in Arkham”
add a skeleton here at some point
about 18 hours ago