To be honest to understand those needs only the most basic understanding of Ruby. And I suspect you wouldn't be saying that if they'd used C style syntax for blocks, you'd understand it because that syntax is so prevalent in major languages.

I think you're making the mistake that because Ruby isn't a C-style language, the equivalent of a Latin script language, it's not understandable. It's just disadvantaged that you can't immediately make some assumptions about what the operators do based on previous experience.