That is not an idiom. It means exactly what it says, although it is probably an exaggeration because it's hard to judge all the fishermen who ever lived and say that one was the best.
Do what ever you want to do.
Does the literal meaning make no sense? Then it's an idiom. Have you ever seen anyone really have a blue face? Nope.
This is not an idiom I have ever heard. Perhaps you mean water cooler talk, which means chat that might occur between workers at the water cooler or anywhere else.
the greatest that ever lived
Not that I've ever heard. All bets are not winners - most bets lose the money.
yehonatan
That IS the best translation - it means happy forever.
hyperbole
An example of an idiom in the book "The Best School Year Ever" is "the apple of someone's eye." This idiom is used to show that someone is cherished or loved deeply. In the book, the Henderson children are seen as the apple of Mrs. Cavanagh's eye, despite their mischievous behavior.
Dennis chambers
Tom Brady
Andre the giant!
Yes he is because he is the best
Michael Jordan
Yes
Ryan Faust
He was certainly one of them.