Found the video you referenced.
https://www.youtube.com/watch?v=8QP2fDBIxjM&list=PLpM-Dvs8t0...
I met the creator Charles Moore a few times. When I lived in the bay area and used to go to the svfig (silicon valley forth interest group) meeting. He would often talk about forth was like solving a puzzle, likened it to sudoku. It is a good exercise for the brain and I highly recommend it.