travel I have a new theory.

My theory is that the Metro maps on the trains are printed in Braille, overlaid with a special time-release ink that only becomes visible after you see it every day.

This explains why tourists need to touch the maps in order to read them.

This morning, just as the train was pulling into the station where I get off, a girl of about 16, wearing a tiny green T-shirt (about size 2T) saying “Me So Corny,” planted herself an arm’s length from the map, deposited her finger thereon, and blocked all methods of egress from the train.