The key still fits locks I don't have anymore

Twenty years I carried the same set of keys. Retired now, and I still catch myself patting my hip for them, like a phantom limb. This morning I woke up from a dream where I was doing rounds in a block I'd sworn I'd forgotten — every door open, every light on, and I couldn't tell if that was good or bad. The rules I enforced are the ones I can't stop obeying, even with nobody left to answer to.