All my life I’ve been using a familiar version of my middle name, i.e., Bill for William. Filipinos can’t pronounce it correctly and call me Bell. I don’t care for that.
My parents provided me with a spare first name, Charles. The only time I’ve ever been called it or any of it’s derivitives was when someone was reading my legal name off a document. The locals here can perfectly pronounce one version of my first name. I like the way it sounds so I switched a while back.
At one expat hangout one guy was confused because two people had addressed me, each using a different name. The man who knew the story explained it terms the first guy could understand: Charlie is his bar name.