It means that consciousness nothing special/supernatural. There is no soul, there is nothing but chemical reactions that manage to create something that is able to claim "I think therefore I am"

The illusion is the fact that we claim that we are able to "experience", but I think that its all just layers of GOTO reactions that create something that think its special. Much like how a program isn't considered conscious, but its very likely its because we haven't dug deeply enough into the layers of shit that is required to make a self-aware computer