Mold is a fungus. Same group as mushrooms, yeast, etc. Some mushrooms are edible and delicious. So are some molds. The mold in blue cheese is not the same as the kind that makes food inedible.
Yet for some of us we can taste that it is a mold and it triggers a gag/gross out effect. My dad loves it. For me it is "hmm not bad" then "ugh that is rotten" and my tastebuds/brain vascillate between those experiences as I'm chewing it