Thoughts about Mermaid

I saw Osamu Tezuka's short anime video called "Mermaid", which is very interesting to watch an old animation look like.

The main characters 

The boy 

What is the main purpose of this video

I think the main idea of this video animation is to emphasize the significance of preserving imagination.  In this video, the main character meets a mermaid through his imagination. After he dived into the ocean, he was apprehended by many police officers and taken to a facility in an attempt to erase his memory of the mermaid.  This country does not allow people to have their own thoughts and the main character looked adolescent in the video, it seems to imply that the free individuality that children have is erased by a controlled society.

What is your opinion happened at the end of the video. 

The boy escapes from the country and moves into a different place where imagination is not prohibited.