Question

What changed Patol Babu's mind about the small role alloted to him?

Answer 1

While Patol Babu was thinking of his small role in the film of just saying "Oh", he remembered the saying of his mentor Gogon Pakrashi, "No role is small".
This changed Patol Babu's mind about the small role aloted to him.

Answer 2

When Patol Babu asked the director to give his dialogues to him so that he can practice it, the director wrote the word "Oh" on a piece of paper and gave it to him. At first, he became furious at this but later considered it and started to practice his dialogue. He saw the reflection of his mentor who told him that the length of a dialogue should not be judged, rather it's the actions which should be taken seriously. Hence, he started to utter the word Oh, oh! over and over with different expressions.