Because the experiment wakes up a sentient mind in the implant via the Web - the very first and true artificial intelligence. And that intelligence starts its learning process at the same time Caitlin starts her vision training. The intelligence - which does not have a name, in fact which does not understand the concept of name, but struggles to comprehend it along the novel and even manages to label Caitlin, referring to her as Prime.

It is a long, painstaking - and sometimes even painful - process, for both sides. And for us as readers as well, for we see their POVs alternating, but they never get in touch with each other. Caitlin doesn't even know that this entity exists - although she suspects there is something novel happening, for she can't controle her implant every time she wants. The intelligence is doing that in its way to emergence.

The story ends in a climax, when the intelligence finally manages to reveal itself to Caitlin, with a simple but impossible question for her to answer: "Who am I?" A question that probably will be answered in the next volume of the trilogy, WWW:Watch, but you will have to read it. I haven't.