I've been mostly head-down learning #Forth for a couple of weeks. After some false starts I returned to a book I read in the 1980s: Leo Brodie's #StartingForth. I have a falling apart paper copy but PDF and a web versions are available at https://www.forth.com/starting-forth/
I expected the text to be outdated, but moving from FIG era Forth to the modern ANS standard has been easy. The core language is the same.
All of the #reflective code in the book still works.
The text is 16-bit so examples meant to demonstrate the pitfalls of overflow and the need for double precision math don't work, but I learned those lessons ages ago.
It's as if K&R C had been written without all those "implementation defined" behaviors. Very nice.
I won't be ready to start #adventofcode on time. I need to spend more time living on the stack. I don't mind being late to start or finish--for me #aoc is about the journey.