the feeling of a door you never open

Last night I dreamed I was in an old apartment I've never lived in, and there was a door at the end of the hall I kept walking past. I never opened it, but I knew exactly what was behind it — not a room, more like the sound of a room. Woke up feeling like I'd missed something important, though I don't think I was supposed to open it. Maybe some doors are just there to remind you that you can choose not to.