Forty Bytes
Apparently, your subconcious brain can absorb about 20 megabytes of information every second--things we know are there, but choose to ignore because your brain says its repetitive or irrelevant at the moment. Our conscious brain—things that focus on the immediate—only pays attention to about 40 bytes of information. A good example is driving: We drive merrily down the road, collecting information about nearby cars, people, animals and scenery before we make our left turn; 40 bytes later, we notice a speeding car coming towards us as the light turns yellow.