###Computers are, in fact, pretty dumb
In our current, technology-rich age, it's easy to take for granted what technology can do. We have technology that can direct us step-by-step when we're driving, taking into account live traffic conditions, technology that can identify constellations in the night sky (even during the day), technology that can connect us into meetings being held many time zones away.
And yet, technology, at a basic level, is pretty stupid. Google Voice and Siri notwithstanding, if we tell a computer something like, "Could you hand me that book?" it would have no idea what to do, without a lot of context pre-programmed into it. If we were to anthropomorphize the computer for a minute--let's call him Bob--and tell him to hand us a book. "Where is the book?" he might first ask. "On the coffee table," you might say.
"I can't hand it to you, there is a coffee mug on top of it." Bob looks at the coffee mug in puzzlement.