As children, we are remarkably aware. We absorb and process information at a speed that we’ll never again come close to achieving. New sights, new sounds, new smells, new people, new emotions, new experiences: we are learning about our world and its possibilities. Everything is new, everything is exciting, everything engenders curiosity. And because of theinherent newness of our surroundings, we are exquisitely alert; we are absorbed; we take it all in. And what’s more, we remember: because we are motivated and engaged (two qualities we’ll return to repeatedly), we not only take the world in more fully than we are ever likely to do again, but we store it for the future. Who knows when it might come in handy?

But as we grow older, the blasé factor increases exponentially. Been there, done that, don’t need to pay attention to this, and when in the world will I ever need to know or use that? Before we know it, we have shed that innate attentiveness, engagement, and curiosity for a host of passive, mindless habits. And even when we want to engage, we no longer have that childhood luxury. Gone are the dayswhere our main job was to learn, to absorb, to interact; we now have other, more pressing (or so we think) responsibilities to attend to and demands on our minds to address. And as the demands on our attention increase—an all too real concern as the pressures of multitasking grow in the increasingly 24/7 digital age—so, too, does our actual attention decrease. As it does so, we become less and less able to know or notice our own thought habits, and more and more allow our minds to dictate our judgments and decisions, instead of the other way around. And while that’s not inherently a bad thing—in fact, we’ll be talking repeatedly about the need to automate certain processes that are at first difficult and cognitively costly—it is dangerously close to m8ndlessness. It's afine line between efficiency and thoughtlessness—and one that we need to take care not to cross

In our youth, we are curious and attentive to every detail surrounding us, not yet distinguishing by the usefulness of the information. As adults, we take everything for granted, ignoring the familiar and walking through life in a mindless state.

I could not help laughing at the ease with which he explained his process of deduction. 'When I hear you give your reasons,' I remarked, 'the thing always appears to me to be so ridiculously simple that I could easily do it myself, though at each successive instance of your reasoning I am baffled, until you explain your process. And yet I believe that my eyes are as good as yours.'

'Quite so,' he answered, lighting a cigarette, and throwing himself down into an arm-chair. 'You see, but you do not observe. The distinction is clear. For example, you have frequently seen the steps which lead up from the hall to this room.'

'Frequently.'

'How often?'

'Well, some hundreds of times.'

'Then how many are there?'

'How many! I don't know.'

'Quite so! You have not observed. And yet you have seen. That is just my point. Now, I know that there seventeen steps, because I have both seen and observed.'

Sherlock Holmes explains the difference between taking your world for granted and observing it scientifically.