What's the meaning of 'thanks for all the fish'.

[Infin1ty]

Hello everyone,

I'd like to know what 'thanks for all the fish' means. It literally means: thank you for all the fish you offered me. What's the extended meaning of it? I saw someone use this sentence: 'Thanks for all the fish' as the title of his resignation paper. Is it an idom?
Could you tell what 'all the fish' stands for? Thanks in advance!
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Today is a gift, that's why we call it the present.

[Cerberus™]

"So long and thanks for all the fish" is a reference to a book from the "Hitchhiker's Guide to the Galaxy" tetralogy. It is just a humourous way to say goodbye; it calls to mind the leaving of the dolphins from Earth saying thanks for the fish they had gotten.

[Infin1ty]

Thank you Cerberus. : )
_________________
Today is a gift, that's why we call it the present.

[Arun_Kumar_45]

Fish is a most often used word in English my friend. I have studied this in a news paper article. I cant remember fully. But I can tell u a situation.

If someone is having alcohol heavily, you can say
He is drinking like a fish.

Please review this message and correct my mistakes in it.
Thanks in advance.