Monsters are real. But our imaginations are our worst enemies when it comes to conjuring up ideas of monsters. Monsters are merely figments of our imagination, either bland or enthusiastic exaggerations of our worst fears. Afraid of drowning? A drowned victim with ugly, long, black hair will come for you and do what you expect. Try and drown you. Afraid of fire? Burn victims attempting to light you on fire would be something to fear. Or just fire itself, an evil incarnate of fire trying to turn you to ash is just as relevant as any other fear. Whether these sound silly or just stupid, they are real fears with manifestations that people imagine due to their lack of facing said fear.
To a person who had a scarring experience with a bird when they were very little, that bird is now a monster, along with all birds in the world as well. They are now just representations of the horrible moment that plagued them for the rest of their lives unless they face it and get over it in a way. Spiders are considered fearful due to their extremely bizarre structure and creepy mannerisms. They are not evil but misunderstood. But regardless they are seen as monsters anyway due to them being the faces of fear in so much media and society today.
Monster is almost always a subjective term. Its definition is literally a beastly, foul, irredeemable, relentless entity or creature that wants nothing but to harm you. Monsters don’t exist without our imaginations though. Our minds always come up with the worst possible, so monsters come about due to our own insecurities and over-the-top ideas of outcomes. We run from monsters because we constantly need something to live for. Fear makes us scared but also yearn to live and breathe. To confront the monsters that people are scared would be too much for some, but it is ultimately what people need. But rational and irrational fears still will remain.
Whether it is something uncommon or understandable, fear makes the most out of humanity because being afraid does nothing but prove that you are human. It is normal to be scared but it is our imaginations that create monsters to slap a wristband on those mistreated fears. And there is a lot of damage to the mind when the monster is manifested. We just end up running from it in the end.