I'm reading Ahoi aus Hamburg (a graded reader for German learners) and it says that the expression “Von wegen Venedig!”* means "So much for Venice!", and from other sites I see translations for "von wegen" such as "no way!", "not a chance!", etc... But my question is: how does the literal meaning of "von" and "wegen" give rise to this meaning?
Another post focuses on whether "von wegen" is polite or not and it seems there are different opinions perhaps based on region. Though many posts there offered translations for this expression, I had trouble gathering from them what might be the origin of this expression (perhaps because so much was in German). I also got no help from the Wiktionary, theFreeDictionary or other sources (btw, I'd be happy to receive advice on where to look)
From Linguee I do find related expressions which make sense to me: "von Rechts wegen" means "as a matter of law" and "von Berufs wegen" means "for professional reasons". In each of these cases the meaning relates closely to literal translations of "von" (from, out of) and "wegen" (because of, an account of) related to a noun.
But without the noun I'm left with "from because of" which makes me think, "Von wegen!"
*In response to a post by c.p., here is more context for how the expression is used: “Willkommen im Venedig des Nordens“, stand auf einem vergilbten Poster... Der Regen hatte genau in dem Moment begonnen, als ich aus dem Zug stieg. Was für ein Glück! Nun wartete ich, dass es aufhörte, aber der Himmel war schwarz und es blitzte und donnerte. Von wegen Venedig!”