Is designing clothes a profession? I would think so, but I remember reading somewhere that there are only three professions.
There are an almost limitless number of professions. Certainly clothing designer is one. If your memory is accurate, I can only assume that the person who wrote that was writing tongue-in-cheek. I wonder what his other two were, since surely "the oldest profession" should have been one of them.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
I posted simultaneously with the post above, not as a rebuttal.
I didn't take it as one. My answer was meant to imply (not very successfully, I now feel) what your second sentence made explicit.