[Zukin]

The human brain is amazingly good at detecting what it wants to find. When you are hungry, your brain focuses on finding food. When you are thirsty, it looks for liquid. The problem is, your brain can become so focused on seeing what it expects to see, it misses things that are obvious but unexpected. Lucky people tend to have a somewhat relaxed view of life. They are less concerned with mundane details and more prone to look at the bigger picture. Ironically, by trying less, they see more.

Seeing The Gorilla - Forbes.com