Oh I mean it as a way to know how the language works.

EDIT for more information:

Being able to write a static blog generator means you have to learn most of the basic skills in a language from the data structures to objects/functions (whatever floats your boat). You have to also most likely interact with outside systems like I/O and databases (if your static blog generator is db driven). You get to familiarize yourself with packaging/modules that the language uses. So yea, I think creating a static blog generator as a next step after hello world would be great

I completely agree. I'm still working on my own but already i've learned a lot (among which, it's a bit more difficult than I expected.)