A frog in a coconut shell Refers to the people who matter most is its knowledge. But actually, with knowledge or experience because of the narrow frame, do not go out to an external lokthat.
Little boxes himself mean, who is very knowledgeable. But then there are a narrow range. Little experience because I did not go out with the external world.
A frog in a well refers to those that they have the knowledge. But I have knowledge in a narrow range Less experienced because it does not meet with the world outside.