There is a legend about the Monster Tree and where Monsters come from. If this were a fairy tale, it would grow in a far, faraway land in the uttermost east or west or at the end of the rainbow or something. But this is a legend and that means it has a grain of truth.
The Monster Tree grows in a world right next to us. The distance between here and there is so thin you can almost see that world. You have seen it. You've seen it in the brief flickers of movement just at the edge of your vision. You've felt it when you thought someone was following you and you turned to find no one. You've dream t it in those disjointed half-awake dreams with too much colour.
The Monster Tree is neither large nor small. There is no size in that world because there is nothing there except the tree. The tree itself has a blood red trunk and dark, black leaves. It grows slowly in silence, bearing no fruit. Instead, a shadow is found between the branches, a shadow blacker than black and more real than reality. And now and then, little shadow fragments break off and drift into this world where they enter the first person they encounter. There, the fragment becomes lodged in the bone, right in the middle of the forehead. This is the monster.
A monster can lie dormant for many years, waiting for the First Thing. In its dormancy, it generates little fears, like a terror of the dark and a horror of spiders. You see them in children who scream when the lights go out and because there are things under the bed. They have an unreasoning and mindless fear that cannot express itself. An adult would tell them sternly "It's all in your mind." And they would be right.
Then comes the First Thing. Not everyone with a monster has their First Thing and these people never know they had a monster except that now and then, they are suddenly frozen with an inexplicable terror.
If however, you have a monster and you encounter your First Thing, the monster will be able to grow. The First Thing can take many forms. It may be an injustice, it may be the sight of death too early, it may the years of lying under the covers, pretending not to hear the screaming in the night. Or it might be you screaming in the night, knowing that others are lying under their covers, pretending not to hear. Different people need different First Things but the important thing is to generate enough grief for the monster to grow.
After the First Thing, the monster grows and spreads through your mind, like damp in a crumbling house. It touches every thought and every deed. You will read invisible words between lines, you will see intentions that are not there and every laugh will be at you. The monster will take everything you see and hear and twist it into crooked brokenness. Of course this does not take place continually or you would know for sure the monster is there. Instead, it comes in bouts, like a sudden sense of un-belonging, a little nagging wrongness in the back of your mind that something is broken and cannot be fixed. This is especially so if you ask other people about the distortions you see and they give you a strange little look and say "It's all in your mind." And they would be right.
But the monster will grow for many years until a big Second Thing happens. Then you find to your horror that though you thought you had grown out of your First Thing and it was all behind you, nothing has changed. And inside, you will still be the same child crying in the dark. And this will be the monster talking. Then Other Things will happen and you know you will never be free and every bridge, every high window, every bottle will be a temptation and a darkness.
Of course if you see you have the monster, you can try to trap it. You can box it with medicines and pile positive thinking and good memories against the door. You can set a guard and tell yourself "I will never let it out again." But monsters are sneaky and if you ever let them get so much as a foot out of the door, they will be back.
A monster can at most be trapped but never destroyed. It will follow you all your life. It will breathe your air and eat your food. It will place it's feet in your footsteps. This is your curse, but this is your blessing: that you can always see other people's monsters. You will see them in famous paintings of screaming people against violent orange backgrounds. You will hear them in music of steel and too much blood. You will read them in books of madness. Something will draw you to them and it will be your monster reaching out to theirs. Then you will know their secret darkness and the pain beneath the ordinary go-to-work-and-home life. And what you do with that knowledge is your choice.