[turndown]

IMO compilers make you a lot more mature in recursive algorithms and trees, and then after that much more conscious about what exactly the code you write resolves to in terms of that languages semantics. Learning how closures work(variable capture and having to traverse the scope stack to find bound variables) is also a positive.

[fuzztester]

Makes sense, thanks.

[turndown]

And that’s just for your first recursive descent compiler. One thing to remember is that you will also one day want extended functionality in your language and either implement C FFI in your language(straightforward or even freely done for you depending on language) and call some C library for the purpose or you have to implement the functionality somehow. So you end up writing a lot of stuff you wouldn’t otherwise.