Once when the education of the Kuru Princes was almost complete Guru Drona called together all his disciples, Duryodhana and his brothers, Yudhisthira and his brothers, as well as all those who had come to learn from him. He had made the image of a bird and kept it in the tree. He called his disciples one by one gave the bow to them and asked them to take an aim on the target of the bird. First he called the Yudhishthira and asked him to take up the bow and aim at the image of the bird kept in the tree. He said to him shoot the arrow only if I tell you to shoot it. Now take aim of it. He asked him whether he saw the bird. To this the Yudhisthira said yes, he saw the bird. Drona asked him what else he saw. To this Yudhishthira said ' I see the bird, the tree, your good self and all my brothers standing here'. Drona was disgusted with this answer. He ordered Yudhisthira to move away. He called his disciples like Duryodhana, Bheema et al one by one and asked them the same question and everybody said the similar answer. Then at last he called Arjuna and asked him to take the bow and take the aim of the bird there in tree. He said to Arjuna to strike the bird only when ordered to do so by him. Now Arjuna took aim of the bird. Drona asked him 'what do you see'. Arjuna replied ' I see the bird'. Again Drona asked him 'What do you see now'. To this Arjuna replied 'I see the head of the bird, only'. After this Guru Drona ordered him to shoot the bird and the bird fell down being hit by the arrow of the Arjuna.