Are You Addicted to Being Tired?

You're Getting Tons of Work Done—Tons of Good, Smart Work

Why You're Hooked: Your boss is consistently impressed with the solid efforts that come out of your wee-hour workathons. Boo-yeah, early-to-bedders! There's an explanation for this superhuman-seeming ability to do more work on less sleep: Sleep deprivation doesn't affect all cognitive abilities in the same way. While studies have shown that it messes with memory, creativity, innovation and complex planning, it doesn't seem to have as harmful an effect on logic and reasoning. Which means we can tackle the reviewing, reasoning and analyzing tasks on most of our work to-do lists without mistakes, and the work is interesting enough to keep us alert...for a while. (Sleep deprivation makes boring tasks even more boring, explains William Killgore, PhD, a psychiatry professor at the University of Arizona and a leading researcher on the topic. This is why the exhausted people in lab experiments who are asked to do nothing more than press a button are snoring through their assignments in no time, and why many of us drift off during conference calls.)

Why You Need to Kick It: The parts of your brain responsible for psychomotor skills, coordination and memory are still suffering from a lack of rest. As you've heard, driving while sleep-deprived can be as dangerous as driving while intoxicated. So even if you stay up all night to finish that report, it won't be much use to you if you crash your car on the way to the office, spill coffee on your laptop or forget your client's name.

Also Note: We're surprisingly bad at judging how sleepy we are, Killgore says. Don't wait for an out-of-control car to clue you in—first try this "lapsing" test (all you need is a chair and a pencil).

You Feel Like 175 Percent After a Night of Zero Sleep

Why You're Hooked: You're talking a mile a minute and sounding confident! Enthusiastic! You're seeing and hearing the world through a new filter, and it's like a Lisa Frank sticker collection...in a rainbow-awesome-colored way.

Why You Need to Kick It: Yes, sleep deprivation makes the world a brighter, more colorful place, or, put more technically by researchers at the University of California, Berkeley: a place where the emotional-processing parts of the brain, like the amygdala, respond to stimuli in a more intense way. This may feel great when the stimuli stokes positive emotions, but Killgore points out that as soon as you hit traffic or a coworker says something critical, your mood is going to careen downhill.