According to a 2011 study, on a typical day, we take in the equivalent of about 174 newspapers’ worth of information, five times as much as we did in 1986. As the world’s 21,274 television stations produce some 85,000 hours of original programming every day (by 2003 figures), we watch an average of five hours of television per day. For every hour of YouTube video you watch, there are 5,999 hours of new video just posted!
If you’re feeling overwhelmed, there’s a reason: The processing capacity of the conscious mind is limited. This is a result of how the brain’s attentional system evolved. Our
brains have two dominant modes of attention: the task-positive network
and the task-negative network (they’re called networks because they
comprise distributed networks of neurons, like electrical circuits
within the brain). The task-positive network is active when you’re
actively engaged in a task, focused on it, and undistracted;
neuroscientists have taken to calling it the central executive. The
task-negative network is active when your mind is wandering; this is the
daydreaming mode. These two attentional networks operate like a seesaw
in the brain: when one is active the other is not.
via "Hit the Reset Button in Your Brain"