Why my brain gets loud the moment I turn the lights off

I used to think my insomnia started at night. Like something suddenly switches on the moment I get into bed. But over time I noticed something. My brain wasn’t actually quiet during the day. It was just busy. Work, phone, conversations, noise, tasks… There was always something covering it up. Then night comes, everything slows down, and suddenly my mind has space to replay everything. That’s when it gets loud. Random thoughts, old conversations, unfinished plans, and worries I didn’t even notice earlier. It feels like overthinking, but really it’s just delayed thinking finally showing up. One thing that made sense to me is that your brain doesn’t like “unfinished files.” If something feels unresolved, even small things, it keeps looping it in the background so you don’t forget it. At night, there’s nothing competing with it anymore, so it takes over. What helped me more than I expected was getting it out of my head before bed. I started just writing things down. Not organized, not structured. Just everything that’s sitting in my mind. Tasks I’m worried about, random thoughts, reminders, even nonsense stuff. It doesn’t need to make sense. It sounds too simple, but it changes something. It tells your brain it doesn’t need to keep holding everything at once because it’s been “saved” somewhere. I still have nights where my mind runs, but this reduced it a lot. It’s like my brain stops trying so hard to remember everything at once. If your thoughts get louder when you lie down, it might not be sleep that’s the problem. It might just be that your brain finally has room to speak.