I used to make fences in Wales, with it famously rocky ground. The fences we made were effectively straight lines which were bound at each terminal point by big posts dug into the ground and braced with side struts. Installing one of these posts could take a full day.

I've worked with Ruby for over fifteen years off and on and the last seven exclusively -- in a large codebase with a fair amount of metaprogramming. We've onboarded engineers, junior and senior, who previously have never used Ruby and it's been interesting to see who does and doesn't have a hard time with it. It doesn't seem to match overall experience and skill level. It's more of a sense that people with patience and a kind of outcome oriented approach (over fixating on why something is done a certain way) will have an easier time unwinding the complexity.

One thing I've noticed, and this is something that seems to bother non-Ruby engineers, is the people that flourish in a complex Ruby application prefer to read code over documentation.