``` If methods were first-class functions, this would work — > method_a would return method_b, which would then execute when x() was called. This doesn't work because Ruby methods aren't objects. ```

Seems the OP is just confused by syntax? we use obj.method(:method_a) instead of obj.method_a, i dont see why requiring a different syntax changes the semantics on this point.

This post deserved so many more upvotes! Fantastic summary, and explained lots of things I didn't quite get really well. Bookmarked.

In your example:

ampersandy(10) do |x| x + 10 end

# => 10

Actually the result should be '20' as well.