I don't think this is what they had in mind when they gathered us in the assembly hall to listen to the memory coach. I guess they invited him to lecture us about study tips for an hour and a half, so we could more effectively memorize historic facts and chemical formulas (that were utterly useless in any situation outside of a classroom). Definitely not whatever this is.

I close my eyes to take a look at my castle - which is very real and at the same time very much only exists in my imagination. Fifteen years ago I learned that these two things don't have to be mutually exclusive, when I first created it. When the coach taught us about the memory palace technique.

What started with a a few sparsely furnished rooms, a few boxes here and there to store information, has evolved into an elaborate labyrinth of winding corridors, hidden rooms and stone stairs, leading deep and deeper into darkness, further and further underground.

Today, there's still very little furniture. Instead, the rooms are filled with boxes upon boxes, piling up to the ceiling, all of them neatly labeled and sorted by date and type of information. I had to rearrange them a couple of times, as to not lose anything in the chaos that was my mind. Also, the idea of labeling the boxes came much later than I would like to admit - and resulted in an immense effort, considering I had already spent years and years filling up the rooms with information and adding rooms whenever needed without plan or structure.

Now, the only way for me to forget something is to forget where I put the information - which happens a lot when you build a damn maze in your head. While the mind trainer was great, he could have guessed that 9-year-olds are no more good at keeping things in the right place than they are at planning a well-organized house. So I guess what I'm saying is that this technique is by no means perfect, but still - I'm now working on getting my PhD with the only side effect that people sometimes look at me weird when I close my eyes to run around my mind palace, to search for a very specific detail that I just know I put in one of the boxes but I just can't find the right one.

What confuses me is how there could be something in here that I didn't bring. I stare at the overturned piles of boxes in the great hall, single loose sheets of paper scattered on the floor. Folders ripped apart. The window is open - wind rustles through the mess, picking up the papers and making them dance. I never open the windows. I've never even touched the windows in the past fifteen years.

My heart races faster as I storm out of the hall, following the trace of loose paper sheets along the corridor and into the library. When I tear open the door, I almost sob at the sight in front of me.

It's destruction. It's so incredibly sad. Books ripped from the shelves, their pages crumbled and torn. Shoeprints from heavy, dirty boots on the delicate covers. Smashed shelves, broken windows, broken lamps. I grab one of the books from the pile, try to wipe the cover clean with my sleeve, but the dirt just smudges and with a scream of frustration I drop the book again.

I can't stand the sight any longer. I need to leave right now, I need to open my eyes again. And for a split second I have this absurd, ridiculous hope that when I come back, everything will be back to normal, that I will find all my boxes neatly stacked again, all books on their shelves.

When I return, nothing is back to normal. It's still all shit. As I move through the palace, seeking a room miraculously spared from the destruction, an odd feeling creeps up on me. A feeling of being watched.

I should be scared, I guess. But I'm just angry. I never considered myself a person capable of violence, but now I'm rethinking it. And that's why I yell all my anger and sadness and frustration into the darkness of the halls.

"Show yourself, bastard!" My voice echoes from the bare walls as I stare. A second goes by until I remember this is my head and I can do whatever I damn well please, and with a flick of my hand, lights turn on and illuminate the corridor. A person stares back at me, flinching at the sudden brightness. A woman, to be precise.

She's not much younger than me. Her face is framed by brown curls, big, dark eyes look at me in confusion. It takes me a while to recognize her, not because she looks so different, but because I don't understand why she's here - in my mind.

"Ruby", I say, and she approaches me, slowly, carefully. "How on earth did you get in here?"

"I have literally no idea. What is this place?" Her voice is softer than I remember. Her frame smaller than yesterday, when she burst into my office to ask on advice on her thesis.

"It's my mind palace", I reply, but taking a look over my shoulder I sigh and correct myself, "well, it used to be."

"It's a mess", she states, stepping past me into the library. She shakes her head, but I grab her shoulder and pull her around, so she has to look at me. Now there's something else in her eyes. Fear?

"You did this, didn't you?" Ruby shakes her head faster, but I tighten my grip. "Don't lie to me, Ruby. It was all clean and organized when I left and now it's a mess, and you are here. I don't remember letting you in."

She slaps my hand away, stumbling backwards. "I have no idea what happened. I did not ask to be here. I haven't touched anything!", she yells. "I tried getting out! I tried to find a door, but there's just none! It's a labyrinth with no escape! I even tried getting out through the windows!" So that's why they were open. I just stare at her, trying to think of the last time we met, trying to make sense of it all. She was in my office. She wanted to get my opinion on her thesis, even though we're in the same PhD program.

I shake my head. No. She's still in my office. I just went to the palace to find an information, the author of a book she asked about. As I open my eyes and return to my office, she has a concerned look on her face. "Are you alright, David?", she asks. "You've been gone for a while." I don't know what to tell her. That she has somehow entered my mind palace and created chaos? She'd never understand.

"I've just got a headache", I simply say, and she nods.

"I get those all the time", she smiles. "That's what getting a PhD does to you. We can get coffee tomorrow if you'd rather lie down a bit."

My heart skips a beat. "What did you just say?"

"Coffee?", she repeats. "Like we always do?"

"Oh, no, no, it's fine. Let's go for a coffee", I say as I stand up and walk around my desk. Her perfume hangs in the air, making me forget what I was just about to ask her. Knocking over another box of things I am supposed to know, creating more chaos.

That's when it clicks.

It's my fault, I realize. After years and years of solitude - I finally let someone in.