Children are always first taught simplified versions of truth first Of course there are exceptions and special situations. For instance, I before e except after c while usually true, isn't always, but we still teach it before going into the exceptions. Same for other grammatical rules (dish-dishes, wish-wishes, but for some reason just fish)
Don't teach the exception before you teach the rule. It confuses children. Yes, someone who you know as a man (and you still should treat as a man) may have period if he happens to be biologically female, but this is an exception, a special circumstance.
