You can not judge a book by its cover. :

This proverb means that it is not right to judge someone or something merely by appearance. Just because the cover of a book is beautiful or attractive, it does not mean that the content inside will be of immense value and vice versa. An ordinary looking book may contain invaluable information. To realize that, one has to read the book fully. Similarly one has to interact with a person before deciding on his capabilities, character and talent.

When Anbu was selected to be the School Pupil Leader by the Principal many doubts were raised about his capabilities by the teachers and staff. He was a new student who had joined the school only that year and the teachers preferred somebody who was popular to be elected as the SPL. Anbu was a tall, thin and quiet boy who had just started making friends in school. Although everyone knew that he was good at studies, he did not seem to be a very dynamic person and certainly did not impress with his looks.

But Mrs. Sathya, the Principal, was very adamant and told the teachers that Anbu was a boy with many hidden talents who could inspire and lead the other students by example.