I recently came across this HFY channel and I love it
I plan to write a few of my own soon but for now, I would like to make a book suggestion.
The Animorphs series by K.A. Applegate
Here is a small sample from "Visser" of a brain parasite taking a human host.
I discovered something strange and disturbing. A huge, deep chasm. It seemed to separate the human brain into two halves. And between the halves was only a small nerve bundle.
Two halves? Why? Why would the human brain be divided in halves? It was irrational design. It made no sense.
Tentatively I reached toward the far side of the brain. I touched it. Made contact.
It was incredible. This second half of the brain was an almost mirror image, but not. It could have functioned all on its own, if necessary, and yet it was in some ways radically different in its memories, its sensory interpretation, even its will. Two almost entirely functional brains in one skull, communicating across a channel of nerves. Not a fully redundant system, almost a second, different brain!
Why? It had to involve specialization, of some sort. And yet I found visual and auditory functions on both sides. I found memory on both sides. Found motor control on both sides.
It was then that I knew I was seeing something new. This brain worked by dialectic. Each half of the brain saw and heard and smelled and touched a slightly different world. Each tended toward specialization, but not a hard, fast split. The left half had more language, but not all the language. The right side had more spatial perception, but not all of the spatial perception.
This mind could argue with itself. This mind could see the same event in different ways. It was insanity! A democratic brain, arguing within itself, with no sure, certain control, only a sort of uneasy compromise. A consensus of disputatious elements.
This brain contained its own traitor!
And, as I began to sift the memories I saw, again and again, the internal argument. The “Should I? Should I not?” debates. The paralysis of internal disagreement.
But I also saw decisions improved as a result of uncertainty. Hesitation and internal discord leading to decisions that were wiser, more useful, than quicker decisions would have been.
And yet that seemed a small compensation for the internal treason and confusion and conflict.
No wonder they kill each other, I thought. They very nearly kill themselves!
It was madness. Humans, as a species, were mad.