About an hour out of San Francisco on the flight to Los Angeles, I made the discovery. I had finished reading the Chronicle , folded and put it beside me, turned and looked out the window, expecting to see the San Joaquin Valley but finding only a sea of clouds instead. So I returned my attention to the inside of the plane, to the overstuffed gray-haired woman asleep beside me, to the backs of heads in seats before me, across the aisle to other heads, and down to the blonde. I had seen her in th