Here is a story of a rich businessman who wants to retire and has to choose from among his three sons the one who will take over his business.  He decided to give it to the one with the best business acumen.

He called all three and gave each of  them a thousand pesos. He instructed them them to buy something that will fill up all the corners of his office. 

The first son bought a tree full of branches and leaves. He had it cut down and brought everything to his father's office. It filled up half of the room.

The second son hired a  laborer to cut as much grasses and bring it to his father's office. It filled up more than half of the father's office.

The third, bought a candle, went to his father's office, turned off the lights and then lighted the candle.

And the whole room was filled with light.