I'd argue that using a pencil and paper (which is a totally reasonable thing!) is not really your memory at that point. Augmenting our hardware with peripherals

I'd argue that using a pencil and paper (which is a totally reasonable thing!) is not really your memory at that point. Augmenting our hardware with peripherals is a useful technique, but it doesn't fundamentally change the constraints; like in "regular" hardware, you're now paying even more per cycle with the equivalent to looking up on an external disk.