We write with lots of DULs (Domain unspecific languages) in our "blessed" language of Unix, which even Windows speaks a dialect of. The unix language is the one which speaks of "files" and "processes", with a grammar known as "the shell", which is what we use to glue together our DULs (which happen to be files and processes). The reason we need "metaprogramming" in the first place is because there's this artificial boundary called "runtime" where all code must be put into a file, because once you warp the file into a process, it's too late to change the code. Fortunately, some clever people have found a way around this, by making processes which can read other files and simulate the operating system.

When writing code, your world is limited by your operating system too. Heck, we're even limited by the hardware, which hasn't changed conceptually since it was created in the 1940s. We're all under the spell of "instructions to the beat of a clock".