Ken Iverson went way-off-the-reservation of programming languages by introducing a symbol for each operation. Each operation is array-based. Unfortunately I can't figure out how to introduce any examples due to the symbol issue. But look at wikipedia: https://en.wikipedia.org/wiki/APL_(programming_language)

Languages that matter will change the way you think. APL really pushes the "need to think" by casting everything as array operations. Unlike FORTH and Lisp, you really need to "carry your problem" to the language.

Normally that would be a problem. But we're striving for the "Why" and "What" level of understanding. This is a language that will really challenge your thinking.

For a mind-expanding experience look for anything by Aaron Hsu. For example, https://www.youtube.com/watch?v=v7Mt0GYHU9A

Aaron talks about "obesity in programming" https://www.youtube.com/watch?v=UDqx1afGtQc He discusses the difference between "essentially hard problems" vs "accidentally hard problems".

If you wanted to do something like write a spreadsheet, this is the perfect language.

APL shows you that "thinking" in a language changes WHAT you can think.

APL is a "must know" language.