-Under Construction- The brain is quite capable and diverse in some ways, but in other ways it's a deceptive, useless jerk.
The human brain (and indeed, all mammal brains, though we will mostly be talking about humans here, since they are the most mental species) is actually primarily made up of fat cells. This isn't because you ate all those Twinkies though, it's because the fat makes a good environment for nerve cells to grow and operate.
While the average human brain is larger than this, it is no subtler, nor more complex...or even free of crayons.
The nerve cells are the big deal here; Neurons, to be exact. Every time you play videogames and watch porn, your neurons are zapping all over the place. Even when you just sit there and stare at a wall, they keep humming away, but looking at stuff makes them do more. They like sensory input. They also benefit from everything that is interactive or dynamic, so when someone tells you to stop playing videogames, you can tell them to shut up while you feed your brain.
Whenever you think about anything specific, use your sensory organs, or even just walk around, there is almost definitely a specialized area that handles the task. Scientists can measure the electromagnetic readings from a human brain, and literally watch chunks of it light up on a screen. In this particular sense, "amazing" or not, humans are almost exactly like some robots. That's no shock though, since people have been trying to model robot brains after human brains for a while.