sister: hello!!! didi how are you???
me: hi!!! I m fine.
( I am in my room and my sister goes out without switching lights)
me: switch off the lights!!!
sister: oh come on di! nothing will happen.
me: it will, you know that why are there so many power cuts???
me: because some people like u don't switch off the lights and fan when going out of the room. this leads to wastage of energy and power cuts.
sister: oh now I know..i ll always switch off the lights when going out of the room