People are hard-wired to pay attention to things in their environment that might represent a risk to their safety or an opportunity for reward. This explains why anything new or unfamiliar gets noticed. We are also programmed to pay attention to things that are relevant to the survival of our genes, which is why we can't ignore the sound of a baby crying and are drawn to anything we find sexually attractive. We are also skilled at picking put out name being mentioned across a noisy, crowded room, in case it means that somebody is interested in us.