While at high school, I had a headmaster who was adept at catching mischief makers. He would walk along the verandah ( what you call corridor or porch ) unseen and with a hawk’s eye, spot the trouble maker in the class room and pounce on him suddenly. Even the most recalcitrant pupil would be unnerved. In adult life, I developed the thrill of watching people unseen from the safety of a window or from behind the tinted glass windows of a hair-dresser’s shop. What else would a poor soul do while waiting for his turn for the barber’s chair? Watching unseen people (you have guessed it right – women included) walking on the road is the only worthwhile pass time.