Learning how Forth is implemented and then implementing my own totally blew my mind. I've fallen hard in love with Forth.

My greatest motivation to learn Forth inside and out is its value in rebuilding civilization if we ever find ourselves in a place where a significant amount of technology has been lost. I don't think there's a more powerful and yet incredibly simple way to bootstrap a general purpose programming environment than writing a Forth. It's a relatively small amount of knowledge that needs to be preserved, compared to all the complexity that would be needed to have compilers, garbage collectors, and all that jazz again.

I mean, that's just my personal take on it.