Dream About Cleaning School Memories

I was back in class (in what I presume to be elementery school) and my desk (which took the form of an office desk rather than a school desk) was really dirty and disgusting. I was an adult here too. There was a layer of what I can only describe as sticker residue on the right of my desk, where the top layer was normal but the underside was sticky. Then there were rat droppings everywhere. They didn't stink so I'm assuming they were there a while. And everything was severely dusty. I only found this when class started so I was carefully trying to clean without anyone noticing. But once class ended and the teacher left, I stayed overtime cleaning and caught the mouse and let it outside. I didn't have the proper tools to remove everything so I had to do it mostly by hand, which was gross in itself but I had to do it so no one thought I made this mess, and so I didn't have to work in it. Then I realized the school was unlocked and I could wander. This was a combination of my elementary and middle schools. When I stepped out, the area felt warm, like the AC hadn't been turned on yet. The elementary school area seemed like it was being used, but less. Then I wandered up to the middle school area, which was A LOT warmer. There was dust flying around everywhere, and almost barren. But then I walked into a classroom. I saw one partially used classroom. Seemed like the lights work and the teacher still uses it with a handful of students, and the air is nice and cool in here. I recognize this teacher as the one that taught me 4th grade and then switched to 7th grade right as I hit 7th grade, and taught us then too (in the dream I kept saying 10th grade, which isn't correct). I saw the picture I drew for him fading on the window. Someone tried to copy it using their art style, which I thought was cheating (in a joking sense) but I'm glad I inspired multiple. There was also a rack of shoes and some of them were mine. I'm surprised they kept them this long. Then I walked back out into the upper wing, which was still middle school. I got hit again with the warm, clammy, and dusty air, which changed my mood from happy to sad. I wondered why they kept building onto the buildings but leaving these other, perfectly useful, classrooms to rot. It didn't make sense. Most of them were barren but with a few desks or signs. But then the one at the end had an old dusty bookshelf. That bookshelf contained memories. One was a picture of my mom and my dad and me (which is a rare sighting). Another was our favorite movie we used to watch. There were a lot of stuffed animals just stuck there. I started wondering why all these were here and how they got there. While that was happening, my mom appeared behind me. I started blaming her for leaving all of these here because she knew I loved these items and why she would forget that I left them here. She looked as stunned as I was that that came out of my mouth, but she had soft eyes in her shock. After my rant, she said quietly "I didn't know that you loved those items so much." I was taken aback by that and said "That was our favorite movie we used to watch over and over on bad days. That was the stuffed frog I got you when you were sick on mother's Day. And that personal photo of us together is the rarest thing on planet earth right now. You think I don't care about these?" With her silence, I started to sob and grabbed all of the items in my arms (almost impossibly) and hurried outside to my car. She quietly started to help and I thanked her in my head of doing so but I was so emotional that I couldn't physically say anything. The last moments in the school I was again sad that everything was left in such a state of disarray and abandoned but glad that I found my lost memories and that one classroom still stands.