You're thinking that air that your nose doesn't think is "fresh" also isn't fresh for the purposes of keeping mold out of your AC system.
You're wrong.
We're telling you about fresh outside air as opposed to recirculated cabin air for the purposes of the mechanical systems of your car, and all you can harp on is that you don't consider the outside air to be fresh simply because it's not what the country's settlers found out in the west in 1805.
The more you insist on not communicating, the sillier you look.