So you show me (or do not show me, instead you just link a website) your ways of retrieving the data encoded by fancy syntax, using a language that has literally almost no syntax at all?

Exactly! The extremely simple syntax of a lisp is what enables similarly extreme syntactic consistency. That consistency, in turn, is what enables lisps' uniquely powerful treatment of code as data, so that programmers can access and transform what would be represented in other languages as "syntactic constructs" and "data values" in a uniform (and, in my opinion, quite nice and expressive) way.

At risk of stereotyping myself, if you like this kind of thing, check out SICP. It is a really good dive into exactly how far you can go with this kind of tool, and also has applicability across the engineering discipline (not just for lisp folks).

I've read through most of SICP, but I never found what's so great about it. Maybe it is that you can apply this argument to any other language as well: Represent your theoretical model as data structures that you control, instead of giving up control to the compiler.

Representing code as data is not very interesting IMO. Code is code, data is data. Granted both are stored in RAM, but they are very different beasts considering how they flow through the machine. Almost any language allows to parameterize over functions (e.g. function pointers), but there is no need to make closures a first class citizen. After all, closures are a brutal abstraction, isolating any context from the caller. When overdone this ends up in a terrible mess where you don't know what's happening anymore (otherwise known as callback hell). Conclusion, use this only as a last resort.