We often here the phrase "Can't see the forest for the trees" to describe someone who is so focused on the details of something that they cannot see the big picture. I don't think this is true for most people in this day and age. Many people have an attention that is so divided they notice neither the big picture nor the details.
And the Details...
Sometime, if you look close enough at the details, the big picture starts to emerge. Then it all makes sense.