Has anyone else noticed that their autistic kids were particularly aware of stuff when they were just tiny babies?

We've just met a friend's newborn baby.  Ever since then, Anne's been spewing forth stories of how much more aware Gaston and Rémi were at the same age.  She has stories of comments from strangers, of Rémi staring at a painting while nursing, of Gaston completely flipping out when she left him at a day care centre at a very young age.  She keeps saying "G & R were so much more aware of the world around them than" the baby we just met.

Little help?  Could it be that autistic kids have a more heightened awareness of the world around them than regular people?  In fact, couldn't that be part of the definition of autism?