tired thinking couple Toms Bauģis via flickr

We write a lot about how eight hours of sleep will make you smarter and happier

But all the energy you gain from a full night's rest might not be good for those who are trying to focus on specific tasks. 

In his blog "A Geek With A Hat," Swizec Teller — a programmer — explains why you can actually concentrate better when your brain is exhausted. 

He says it's because your brain is so tired, it has to focus. In other words, "there isn’t enough left-over brainpower to afford losing concentration."

Teller says: 



"Conversely, when I’m slightly tired, I just plomp my arse down and code. With a slightly tired brain I can code for hours and hours without even thinking about checking twitter or facebook. It’s like the internet stops existing."

Basically, when you're full of energy, you lack concentration because your attention is pulled toward too many directions. You think you're multi-tasking, but you're actually just switching from one task to the next, which, ultimately, takes a longer time to compete individual tasks. 

However, when you're exhausted, you don't have the energy to wonder about what the rest of the world is thinking, therefore, you're not checking your email or Twitter accounts or browsing the internet as much.

And you know you can't take a break — or you might risk falling asleep — so you focus on finishing the task at hand. 

"...When your brain isn’t working at full capacity it looks for something to do," Teller writes. "Being tired makes you dumb enough that the task at hand is enough."

NOW SEE: 19 successful people who barely sleep >