Losing after winning is the worst feeling possible. This is how I feel looking out of my window at a thick pall of black smog engulfing my city. It was this time of the year, exactly 15 years ago, when Centre for Science and Environment (CSE) began its right-to-clean-air campaign. The air in Delhi was so foul one could hardly breathe. That was a time when air pollution was an unknown curse. Not much was known about its nature and the toxicity of the air contaminants.