Module methods

my_module.rb

class Module
  # `hello` should be readily available within all regular classes
  def hello
    puts 'Hello World'
  end
end

# `special` should be available within all regular singleton classes
class Module
  class << self
    def special
      puts 'This is the special method defined in Module.singleton_class'
    end
  end
end

class MyClass
  hello  # => 'Hello World'
  # special  # this correctly raises an error here
  # special should only available in MyClass.singleton_class and it actually is.
  # However `hello` method shouldn't be available in `MyClass.singleton_class` (only in MyClass) but yet it is. Why?
  class << self
    special # This only works here as it should
    hello  # but strangely this works too! It shouldn't though...
  end
end