Sure, but the thought experiment is more that you write down 128 bits, generate the 1gb, then eat the paper containing the 128 bits. You now have 1gb that behav

Sure, but the thought experiment is more that you write down 128 bits, generate the 1gb, then eat the paper containing the 128 bits. You now have 1gb that behaves a lot like it is 1gb of entropy, even though it still isn't.