Ruby code is readable. So some of the documentation in say, Java, isn’t as necessary.
I'm confident that you're either an outlier or have simply come across a terribly written or badly formatted Ruby codebase - considering Ruby (and Rails which followed the same principles) was created with the purpose of being highly readable (made for humans [1]).
What is advanced IDE highlighting? Do you mean.. colours? And memorising methods - huh?
I really struggle to see how you can't tell which lines here are methods - https://gist.github.com/davidlares/5d136fa54572ad98e711e3684...