Depending on when you're watching this video, you may have a very different reaction. Just rolled out of bed any watching this first thing in the morning? You're probably dealing with some sleep inertia that's slowing you down. Watching this later in the day before lunch? You're sharp as a tack, dude! At least, that's the takeaway from this AsapScience video that takes us through a day in the life of the human body. The body has rhythms all its own, and it's not a surprise to say that the cycles of our body drastically affect our mood and mental performance.
It's a great argument for taking more naps, too.