No memoization between associations?

test.rb

class Group
  has_many :things
  
  # external data would look like:
  # {
  #   things: {
  #     1: "some data for 1",
  #     2: "some data for 2",
  #     etc...
  #   }
  # }
  def external_data
    @external_data ||= begin
      puts "making api call to get external data"
      results = SOME_API_CALL.body
    end
  end
end

class Thing
  belongs_to :group
  
  def data
    @data ||= group.external_data.things[id]
  end
end

# Invoke:

> @group = Group.find(1)
> @group.things.each { |thing| puts "#{thing.id} = #{thing.data}" }

# Expected Results:

=> making api call to get external data
=> 1 = some data for 1
=> 2 = some data for 2
etc.

# Actual Results, API call is made for every has_many assoc:

=> making api call to get external data
=> 1 = some data for 1
=> making api call to get external data
=> 2 = some data for 2
etc.