When I was being measured for my first suit (in my early teens) the tailor asked ''Which side do you dress on?'',I had no idea what the hell he was talking about.I thought he was having a joke and expected him to say ''The outside!'' or something equally weak.Instead he asked if I was right handed,when I said I was he replied ''Right handed people usually dress to the left''.I thought I was having a suit made by a madman.
I don't know what I was wearing but it's usually obvious which side I dress on.