What the hell is "death", is it when I see an animal that isn't moving or breathing and with flies all over it?
That's not an animal. It's the matter that used to be organized in such a way as to comprise an animal. Now it's just a pile of rotting tissue. When it's a human we call it a "corpse," but that's just a polite word for a rotting pile of tissue like "breast" is a polite word for a mammary gland.
"Death" is the cessation of life. It's something that happens and then it's over. It's not a condition. What we call "dead animals" are not animals in a certain condition, they're piles of rotting tissue. The same goes for what we call "dead people."
After you die, you're not "dead." You're not anything. You don't exist. Rather than saying "He is dead," it would be better to say "He has died." To say "He is dead" makes it sound like he still exists and is merely in a different state than the last time we saw him.
This problem is a linguistic accident. "Dead" was originally the past participle of "to die." Some verbs used to form the perfect tense using "be" as the auxiliary verb instead of "have." We still have a few archaic instances of that, such as "Joy to the world, the Lord is come," instead of ". . . has come." So to say "He is dead" was merely the grammatically correct way of saying what we now would phrase as "He has died." Somewhere along the way we began using the past tense of die, "died," as the past participle, normalizing it to the standard English paradigm, and we began using "have" as the auxiliary verb for all perfect tenses, except in Biblical quotes. So we began saying "He has died" instead of "He is dead." But at the same time we began to regard "dead" as a condition rather than a completed action, so "He is dead" came to mean "He is in a special condition that people achieve after they have died."
There is no such condition, this is just a fantasy provided by religion. To say "He is dead" is to unconsciously buy into that fantasy. It's better to say "He has died."
Sorry, I can't conceive of this thing unless I look outside myself at "dead things"; I can't, somehow, manage to connect this external reality with any internal pov, that includes that internal pov and the eternal "reality".
That's because there is no internal POV. You have to exist in order to have an internal POV. Death is the cessation of existence.
We do indeed talk about "dead things" as a shorthand way of referring to rotting piles of tissue that used to be "live things." It's just another way of saying "meat" or "offal," depending on whether the culture you belong to considers it edible. In America a sheep's stomach is offal, but in Scotland it's meat. In both places it's a piece of a "dead thing."
We also sometimes use "dead things" to refer to inanimate objects that were never alive to start with. I think that just makes more confusion so I don't talk that way. "Non-living things" is much more precise and scientific.
I don't understand. What are you trying to accomplish? Death will happen whether or not you understand it. Once you cease to exist, none of this will matter to you anymore because there will be no more "you."
If you're trying to understand death, it's rather simple: First you're there, then you're not. Like a house that's been knocked down by a wrecking ball. The bricks are still there, but the
organization of the bricks that made them comprise a house is gone. Your tissue will still be there, but the organization of the tissue that made it comprise a human being will be gone.
When you die, you're not "dead." You're nothing. Literally.