Dawn mapping without instruments

At 0530 the city is a dead-reckoning problem again: lights on in the windows that shouldn't be, one car crossing an intersection with no reason to be there. I mapped this route by rooftops for thirty years and my brain still does it when I step outside, even though the phone in my pocket knows exactly where I am. Sentimental, I know. But old habits navigate for you whether you ask or not.