Nice, 100 people show interest in what was meant as a showcase project for the STM8 Value Line eForth project!
It's true, Forth differs a lot from procedural programing languages like Java, C++, C, Pascal, or Fortran. If you put the religious wars about programing languages aside, you'll see properties of scripting (Bash, BASIC, Perl, Python), REPL (LISP, Clojure), and ... assembly. It's not a panacea, but for some things it's very good.
I'd like to encourage you to get one or two of the green DCDC boards, an ST-LINK V2 adapter, and a serial interface adapter. With budget delivery, this will cost you about $4. It would be really nice to some companions on this journey, and to get some feedback about which features are needed most, or which points need better docs :-)
EDIT: 102 people now. Thanks guys! I forgot to mention the two capacitors and the two resistors. If you don't have an assortment in your lab anyway, here and here are examples for what you'd need for this, and for other projects (you may also ask a friend for some of these half-a-penny items).
Does someone know of a Hackaday page with recommendations for an "electronics starter kit"?