kyon chalti hai pawan, due to varying pressure zone formation. kyon jhoome hai gagan, because of earth's revolution. kyon machalta hai mann, problems with respiration. na tum jaano na hum. but i just gave all the reasons! kyon aati hai bahaar, because of a change in season, kyon lutata hai karaar, suffering from mental tension. kyon hota hai pyaar, because of opposites' attraction. na tum jaano na hum. seems you didn't pay enough attention. kyon gum hai har disha, because you have a poor sense of direction. kyon hota hai nasha, because of drug addiction. kyon aata hai mazaa, brains response to physical sensation. na tum jaano na hum. even after all the explanation ashish