> the language itself is surprisingly simple. the difficulty people have with it is that it’s functional, not that it’s nix.

I wrote down "what I wish I knew when learning Nix", and realised what had initially confused me:

Some people are confused by immutability when learning functional programming. e.g. Programs involve changing things, but then immutable stuff doesn't change.

With Nix, packages get built and installed to the store. In other solutions, this is done by running a command like "install package", or by having some file describing the package and running "install this"... but with Nix, packages are so integral to the language that they're built as part of just evaluating the language expressions, and (before flakes) the language didn't really have a "main file format" the same way that programming languages do, or that Terraform does.

With functional programming, pure functions have no side effects. With Nix, an implicit side effect of evaluating code is that packages are built.