That's the problem: you don't seem to have enough experience.
So as far as actually talking about my point goes, what exactly am I missing? There are small differences but I've never seen a language that I couldn't get up and going in over the course of a week.
How much experience do you think I have? I've used plenty of languages, and I'm well aware that there are nuances.
That's because you either used the languages superficially, or use only very similar languages, probably of the Algol family (e.g. Ruby, Python, PHP, JS, etc).
You won't get very far with Haskell "over the course of a week". Or APL. Or Idris. Or Erlang. Or Lisp -- or any other language that's not a mere Algol derivative with some different bells and whistles. And even those have their idioms, of course, that one needs much more than a week to get competent with, but, it gets worse when we expand languages to not be "mainstream Algol derivatives". One would only be using languages like Smalltalk, OcamL, Scheme, Scala, Self, etc, superficially without getting into their idioms and nuance, which wont happen in a week (and can take years to really master).
Based on the fact that you think all programming languages are essentially the same. That's just a ridiculous claim and it immediately exposes you as someone who's only used a couple of Algol derivatives.
1. I don't think literally all programming languages are the same
2. I have used Haskell, and am very aware of every language listed in the other replies to this comment, so you're completely wrong.
I kind of thought this community was better than this, to be honest.