Highway hypnosis is the official term. You drive a familiar route and arrive without recalling the journey. Cognitive psychology explains it as automaticity: well-rehearsed motor sequences run without conscious involvement, freeing attention for whatever else the mind is doing. This is correct. It is also incomplete. The strange part is not that the driving happened on autopilot. It is that no record of it was retained. There is no faint impression, no fragment that can be reconstructed. The fifteen minutes are simply not there. A computer would describe this as not allocating storage to a low-priority background process. A novelist would describe it as a small horror. The simulation hypothesis would suggest that the system does not bother to render high-fidelity experience for stretches it considers procedural. You are conscious during these stretches. Or so it seems. But the only evidence is your conviction that you must have been. There is no ledger.