Are you sure that the parent was comparong humans to cells? It strikes me more as this: "human intelligence is run by a network of nerve cells which are complex

Are you sure that the parent was comparong humans to cells? It strikes me more as this: "human intelligence is run by a network of nerve cells which are complex but could be modeled in all of their conplexity". So if you could model enough of these, you would get a functional replica of a human brain.