"Animals never spend time dividing experience into little bits and speculating about all the bits they've missed. The whole panoply of the universe has been neatly expressed to them as things to (a) mate with, (b) eat, (c) run away from, and (d) rocks."

Next Quote

In effect, dividing your attention means that neither (or none) of the things you're working on is really getting the full effect of your intelligence, and that it in the end takes you longer than it would if you did one thing at a time.

— James Surowiecki