Taking or carrying coals to Newcastle is an idiomatic expression that means doing something that is completely unnnecessary, pointless or superfluous. The German equivalent of this is Eulen nach Athen bringen/tragen – to take/bring owls to Athens. Are there similar expressions in other languages?
Newcastle-upon-Tyne used to be a major coal mining area and the UK’s first coal exporting port, and was first associated with pointless activities in Thomas Fuller’s 1661 The history of the worthies of England: in which he wrote, “To carry Coals to Newcastle, that is to do what was done before; or to busy one’s self in a needless imployment.”
An idiomatic way of saying that you’ve missed something such as an opportunity or an event, is ‘I’ve missed the boat’ or ‘that ship has sailed’. In German, the equivalent is der Zug ist abgefahren – the train has departed. A similar expression is used in Swedish – tåget har gått – the train has left. What about in other languages?
By the way, a good place to find information about English idioms is: www.phrases.org.uk