An 80 year old man was sitting on the sofa in his house along with his 45 years old highly educated son. Suddenly a crow perched on their window.
The father asked his son what was that, and the son replied that it was crow. After a few minutes, the father asked the same question, and the son said that he just told him what that was, it was a crow. After a while, the father sked his son the same question, and the son got irritated and rebuffed to his father that it was a crow.
A little after this, the father asked his son again. Then, the son started shouting at his father. He yelled why he kept asking the same question over and over again, even though he told him the answer. He asked his father if he was not able to understand it.
A bit later, the father went to his room and came back, holding an old tattered diary. He had it since his son was born. He asked his son to read the opening page. This is what it said:
“Today my little child matured three was sitting with me on the couch, when a crow was perched on the window. My Child asked me 23 times what it was, and I answered to him each of the 23 times that it was a Crow.