Why does the Room of Requirement use the same hiding chamber for everything?

Question

The Room of Requirement has a particular chamber for people to hide stuff. Everyone needing a hiding spot is redirected to the same chamber. It goes without saying that several hundreds of people have used the same chamber for hiding stuff.

It makes sense - what better place to hide your secrets than under a pile of other people's things?

... Well, it makes sense today, because there's so much junk. But what about the first users? Let me put it this way:

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Suppose that the first ever user is a boy A:

A needs to hide something, and discovers the Room of Requirement. There, he finds a nice, empty space where he can hide his... oh I don't know, dead body or something. A places the dead body there and leaves the room happily, knowing that this magical chamber will do as he wished: keep the body hidden.

Then B, another boy, needs to hide something. He finds the Room of Requirement, and is granted access to a nice chamber... with a dead body in the middle.

The point of a hiding spot is for your possessions to not be found by anyone. This doesn't make sense for the first hundred of users of the Room of Requirement, because one user will find the possessions of the previous users.

It takes several hundred users to make this a good hiding spot, but for the first ones this must have been a bad one, because the objects are right there in plain sight, rather than a large pile of garbage.

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My question is, then: why did the Room of Requirement use the same hiding chamber for all the people that needed to hide things? If A asks for a place to hide his corpse, obviously he wishes nobody to find it. Yet B will find it.

Answer 1

We know that the Room of Requirement can only be used by someone who really needs it, and only for their specific needs.

“Dobby knows the perfect place, sir!” he said happily. “Dobby heard tell of it from the other house-elves when he came to Hogwarts, sir. It is known by us as the Come and Go Room, sir, or else as the Room of Requirement!”

“Why?” said Harry curiously.

“Because it is a room that a person can only enter,” said Dobby seriously, “when they have real need of it. Sometimes it is there, and sometimes it is not, but when it appears, it is always equipped for the seeker’s needs. Dobby has used it, sir,” said the elf,…

^{Harry Potter and the Order of the Phoenix, Chapter Eighteen: Dumbledore's Army}

We also know that the Room of Requirement can also be discovered by someone who does not need it if they knew about it, because that's how Umbridge gets to know about Harry's Defense Association (a.k.a Dumbledore's Army or DA) in the same book.

We also later see how Dumbledore's Army, this time led by Neville Longbottom in an attempt to fight the new regime in Hogwarts in Deathly Hallows, is able to keep DA safe in the Room of Requirement away from the Carrows.

“It’s a proper hideout, as long as one of us stays in here, they can’t get at us, the door won’t open. It’s all down to Neville. He really gets this room. You’ve got to ask it for exactly what you need — like, ‘I don’t want any Carrow supporters to be able to get in’ — and it’ll do it for you! You’ve just got to make sure you close the loopholes! Neville’s the man!”

^{Seamus Finnigan in Harry Potter and the Deathly Hallows, Chapter Twenty-Nine: The Lost Diadem}

Taking all that into consideration, I think that unless you asked the Room of Requirement to make sure that whatever you're hiding must not be accessible to anyone else (by "closing the loopholes"), someone else could indeed find it (perhaps the Room considers "hiding" a vague term?). If you do ask it, the Room will present you with a quite different "chamber", probably an empty one, but nevertheless making sure that no one else could find what you were hiding. The thousands of students probably weren't careful enough while hiding the objects they weren't supposed to be possessing in their haste to avoid trouble. Even Voldemort didn't fuss while hiding one of his precious Horcruxes (although he never expected anyone to find out about them, anyway).

That said, it would make sense that unless you were very careful while asking the Room exactly what you want/need, the thing you want to hide would land in the same place as everyone else's cruft. In your example, B would definitely not be able to see the dead body if A was careful enough. He would probably find an empty chamber just like A did, depending on whether or not A wanted to make it hard to find for himself (the seeker's "request" to the Room; and I bet he did, it was a dead body, after all).

Answer 2

I don't think there is a canon explanation - but why couldn't the room just have been full of random stuff? Piles of things are good to hide a single additional item - so for A the room created random piles of items. And B got the random piles + A's body, and so the story went on... (Maybe the room removes some of the beginning random elements to make room for all the additionally hidden things, but that's just detail speculation...)

Answer 3

As this is a logical question here is a logical answer that I believe is NOT contradicted by canon, though it may not be directly supported either. Time can be modified in universe (Time Turner).

The room of requirements, like many magical things, exists outside of time and space, as muggles experience it. Everything that has ever been placed in the hiding chamber of the Room of Requirement and not removed has always been there, EXCEPT when the person who placed it there entered to drop it off (hypothetically, it could have already been there also, but the existing versions pops out of existence when 'now' converges with the drop off)

All the 'junk' is/has always been there. When Boy A needs a place to hide his dead body, the room/chamber is full, and when boy B enters the room/chamber is full.

Now the only problem with this theory is that some things leave the room/chamber after being hidden there. While I will not say that items that have left, are no longer 'in' the room, the item would be impossible to find to anyone whose external timeline is after the timeline of the person who found it.

Answer 4

I always thought that the room already provides generic items to hide the important things students bring to hide. Remember not everyone knew this was a special, magical room either. We could assume some people were looking to get rid of old stuff and found this room. It's a room to get rid of things. Not just to hide them.

Even if Boy B saw Boy A's dead body he wouldn't know that it's Boy As. He would think "Oh there is a dead body, weird." He would not connect the dots between the body and Boy A. So really everyone's items are safe because no one knows whose item is whose. This is why the diadem horcrux is safe there. To everyone, it looks like a ordinary diadem. No one would know that it's Ravenclaw's lost diadem and certainly not know that it's Voldemort's horcrux.

Also think about it this way. Neville closed all the loopholes during Deathly Hallows when hiding from Snape and the Carrows but in regards to the room of hidden things there are two other ways the room protects the items from being found. 1. Another person needs to know that someone hid something in the room. 2. That person needs to know exactly what is hidden to find the item and get access to the room.

Let's go back to your Boy A and Boy B example. If Boy B knew Boy A hid a dead body in the room then all he needs to do is ask the room to reveal "the dead body Boy A hid". That would only work if Boy A hadn't asked for a hiding place where no one would ever find his item too.

Answer 5

First of all, I can't answer whether all the things in the Room of Requirements are hidden stuff from different students.
But I can surely answer why Room of Requirements shows up the same chamber every time someone wants to hide his/her possession.

Consider an in-universe example: Harry wants to hide a book, while Voldemort wants to hide a horcrux. One a source of wisdom while other a source of desecration & evil.

Consider another in-universe example: Gringotts bank. One chamber/locker holding the Philosopher's stone (a good thing in the right hands) while another separate chamber holding a horcrux (again, an evil object).
In the Gringotts bank, in an ideal scenario of 100% security & sole legal authority, a person cannot access someone else's vault/chamber/locker.
So, if someone's life is hanging in the balance, he neither has the authority nor the entitlement, and definitely not the hope of getting to the Philosophers stone.
With same logic, if Voldy's life is hanging in balance, Harry neither has the authority nor the entitlement, and definitely not the hope of getting to the horcrux.

Gringotts is a man made institution and abides by unambiguous, definitive, dysfunctional, and strict laws. The Room of Requirement is not a bank for storing your precious stuff. It's a self evolving magical place.
It was designed by the founders of Hogwarts and it could not have been meant as a discretionary vaulted place.
You can hide your stuff in an innocuous place but be sure, anything naughty and there will be a means to find it. It can hide a good object and an evil object equally well and it also gives a way of finding those things. Maintaining balance in nature.

Room of Requirements was neither a "Good" place nor an "Evil" one. It could, however, at its best, be a just place.

TL; DR; Nature or as atheist would like to call it, God

Answer 6

When Tom Riddle needed a place to hide the diadem the Room provided what he needed; a huge room full of junk where an ordinary-looking box would not be noticed. Its not that everything else in the room was hidden, more that that version of the room was generated with vast amounts of junk already in it.

Answer 7

Well the first hundred users or so asked for the same thing, but didn't know anybody had used the room. They found out soon enough though. Then, when people asked for something else, they'd get it. I don't fully understand it at first either, but over time I understood. But I'm a logical person. See, if you try to incorporate some logic, you'll understand better. If this answer doesn't help, let me now. Just try to go easy. I only didn't understand at first because I was eight when I got that far.

If you need a full explanation, you can go to Pottermore.com and see if somebody there con help you. But don't ask Prophecy Seeker. That's me. So To summarize, they asked for the same thing, so they got the same room.