Arjun, the best student

While in Gurukul, once the Kauravas and the Pandavas were given an archery test by their Guru, Dronacharya. They were asked to aim at the eye of a toy bird which their guru had placed on the branch of a tree. 

When the teacher asked them one by one that what did they see, with the exception of Arjun, all the others claimed to see the sky, trees, the bird, the leaves, the branches, fruits, etc. 

Only Arjun said that he just saw the blackness of the bird's eye. After that, he was permitted to shoot at the target, which he accomplished successfully.

Thus he took the first step in becoming the best and favourite student of Guru Dronacharya.