The train doors hissed open. I stepped aboard and sat on an empty bench as we glided out of the station.

Opposite me, a decrepit old fellow was sprawled on the carriage floor, sorting his stash of grimy shopping bags. A long bulbous nose gave him an air of Jimmy Durante, minus the felt homburg. His long beard was a tangle of white wisps. A red-checked parka and black tracksuit pants, the knees peppered with holes, did little to pad his raw-boned frame. The soles of his black sneakers had worn down to reveal threadbare socks and a glimpse of grubby feet. He gave me a sly glance with one bloodshot eye.

With arthritic fingers, he peeled open a plastic pocket and slid a collection of small sugar packets into one hand. I watched, fascinated, as he laid them end-to-end, domino style. With a grunt, he swept up the sugar packets and lined them up like soldiers instead. Satisfied, he reached for another plastic sleeve.