In the whole of your adult life, how many times did you use the Avogadro’s law? During your entire work life, did you find any use for the date of Battle of Panipat? How many times did you have to recall the formula for Barium Hydroxide?

If you are a school teacher or a professor specializing in these subjects, it is possible that you used these facts. But that cannot really be classified as a real ‘use’. If the final…