Woah.
If your brain's cortex were laid out flat, it would be about the size of a newspaper page.
The cortex is the outer layer of the brain and is made of grey matter.
Flickr: 24oranges / Creative Commons
Your brain is 60% fat.
And its fatty molecules are among the most crucial to its ability to perform.
Flickr: jepoirrier / Creative Commons
Over the course of human evolution, brain size has tripled.
Your brain uses about the same amount of power as a 15 watt light bulb.
Not saying that you're dim, but...