In 1928, the year Fleming discovered and then rejected (three times) the penicillium that makes lifesaving penicillin, there were about two billion humans on the planet.
That year , tens and tens of millions of miscarriages and premature deaths were caused or hastened by bacteria and virus.
Everybody knew somebody who had died from bacteria or virus - everyone knew the primeval fear of raging epidemics.
That same year tens and tens of hundreds of people died from fungus - their individual deaths - spotted here and there almost at random- usually just seen as the result of eating 'bad' food.
Except in a few remote cultures, almost no one knew anyone who had died from fungus.
Yet in the world of cultural horrors and monsters , did we see this reality reflected at all ?
Of course not - no giant viruses or bacteria stalking the innocent maiden of movie screen and genre literature ---- it was always some faceless, shapeless, smelly, flowing, slimy gooey thing : fungus, in other words !
One suspects that this is because the virus or bacteria seems invisible ( though if we walk across the rocks of a shallow stream, the slime on the rocks is bacteria made visible).
But while most mold colonies are as equally invisible as bacteria colonies, the fungus frequently grows to highly visible sizes - easily drawfing even the bacteria colonies force feed to visible size on lab petri dishes.
In our homes or out in forests , molds easily grow big, fast, furry and slimy --- and always are extremely colorful.
The slime mold (a mold indeed as the word is understood by all but experts, just not a fungus mold) actually moves and quivers - a real life monster just waiting to be scaled up to the movie screen.
But molds are definitely the least harmful to humans of the big four of microbes life forms - more a danger to plant life than to humans and animals.
They simply are - to turn a phrase around - in sight and in mind ....