Naeglerium fowleri
You bastard. You are not a man. You can never be a man. You will never man up, will you?
You are this parasite living off of my mind. You will never get out of my brain and you never have been able to and neither can I drag you out of me myself. I will be left with no choice but to study you closely until my demise.
In the heat of my fever, my blood boils not only from the prostaglandins but also the rage I hold towards you. I think of you ad nauseam and vomiting my fluid of words would surely relieve me of the bowel discomfort. Unfortunately the headache never ceases even with the painkillers because you're taking up a lot of space in my head.
You're this brain-eating parasite living in murky waters that's apparently found its way to thrive off my biological system. You nestled yourself in the sinusoidal mucosa of my skull where my mucus is undrained and environment is dark and warm and suitable for your encystation before my bodily defenses are dropped, enough for you to rethrive.
Your excystation happens so quickly just as you fall into another slumber that it's almost impossible to fight against you. Your trophozoitic form, transient yet insidious, I can never get a grasp of you. Your cysts pretty much drug-resistant, this empirical antibiotic I self-administer might just induce multidrug resistance in other strains next to you.
Prophylactic treatment is none the more effective thus having all me myself, my health, my time, and my energy wasted off while you live off liberally in the crevasses of my skull without any sense of guilt, or at least appearing to be without any. I mean, to be fair you're too monocellular of an eukaryote to have or show any conscience.
You in your colony of protists can do no more than huddle each other and live as a conforming herd, afraid that any deviation is assumed mutation, putting you at risk of estrangement, worse yet, predation, by your own fellow kins and clones. You live without individuality for the sake of survival just as you thrive off someone else for the same survival.
For this same reason you cannot completely kill me off as you still need me. You will never stop wasting my time either because you have no sense of time. You don't need any centrioles to divide by binary fission, making your life almost seemingly infinite. You have all the time in the world to fool around despite how much you claim to be mortal.
One of these days, it's either you lyse and consume every piece of tissue in my nervous system to leave me in a vegetative state before succumbing to respiratory paralysis, or I take you down by my body's own cytokine storm as a means of defense, unintentionally killing myself in the process. Both will have me end up dead, maybe only then can I get you out of myself.