Years ago, as a (traditional) designer trying to learn how to code, I spent what felt like an eternity trying to wrap my head around JavaScript. This was in the ES5 days. After a lot of effort I could usually do something approximating what I wanted, but there were a lot of stumbling blocks that got in the way of really understanding what was going on.
Once I learned Ruby, the fog parted and everything started making sense. Compared to JS, Ruby was transparent. Everything was just a bunch of objects sending messages back and forth to one another. The simplicity of defining classes and methods made it easy to think about how a program could model aspects of the real world – domain modeling, abstraction, etc. One early experiment I recall was using Ruby's built-in Enumerable and Comparable modules to represent a deck of playing cards in code (complete with > and < methods which respected suit, royalty, etc) – this was a real "aha" moment in my learning process.
Reading code written by others was much more straightforward (making it easy to learn from the masters), and writing extensions/plugins to existing tools to add features that I needed suddenly became feasible. Books like David Black's "The Well Grounded Rubyist" and Sandi Metz' "Practical Object Oriented Programming in Ruby" were great, accessible introductions to the art of programming.
I don't write much Ruby any more, but I'm in total agreement with Dave Thomas here. Ruby for me was the "royal road" into learning how to program, and it continues to inform the way I think and write code in other languages. As a non-CS person, I can't think of a more accessible way to learn about software development.