From a practical perspective, I believe the whole point is that an idiom is fundamentally different. If you are a non-native speaker, you can look up a word you don't know. But if it's an idiomatic phrase, like "waiting for the other shoe to drop," looking up each word in the phrase does you no good. Studying fables etc. is a great way to learn them.
Same here, and another one that irritates me is "being left high and dry", which is a bad thing. But I envision high and dry as a good thing, isn't that where you would want to be in a storm or at sea?
Truth be told I never actually looked up where a lot of these idioms come from. I just heard other people using them and then I started to use them too.
But not if you tied your boat up in a harbour, and then when the tide went out, you can't sail it because it is high and dry sitting on it's hull instead of floating.
Interestingly, the first given translation is itself an idiom (lit. "to wait for the thick/fat end"). An idiom I understand, even though I had no idea where it's from; I looked it up, it relates to corporal punishment. The second translation is a more generic one.
The second translation is a biblical reference, where a "Hiobsbotschaft" implies receiving news of a further tragedy, invoking the Old Testament character Job (Hiob), whose faith was tested by suffering great losses.
Unfortunately neither of these help to understand the English shoe idiom which I, as a native English speaker, have no clue about.
You can look up the entire phrase or just ask someone. There’s no need to know where it came from, although it might make retention easier, or comprehension better. Nothing beats time spent immersed in the language and just asking questions or looking at context when something seems odd. Living languages aren’t static targets either, you’ll sound formal or just plain strange if you elevate dictionary definitions over experience and practice with common usage.
In some cases, there's an equivalent idiom in the native language, and while the scenario may be very different, the underlying similarity is readily apparent.
