Babies come into the world with a lot of pre-loaded programing, but they still have a lot of learning to do. As the saying goes, little pitchers have big ears, because they're constantly soaking up information.
As such, infants are actually more conscious of the world around them than adults. It's just a different sort of conciseness, one more like a lantern than a flashlight. Their brains are soaked in neurotransmitters, brimming with neural connections as they immerse themselves fully in the sense world around them.