We’ve all had nights where no matter what we try—counting back from 100, meditating, drinking tea—we just can’t fall asleep. The next day we feel like a zombie shuffling through dense fog. This video from BuzzFeed details exactly what's happening to your body when you don’t catch any zzzs. One sleepless night impairs movement and focus the same as when you’re drunk. Missing two consecutive nights messes with your speech, so you start to stumble on words and forget what you were talking about.
See What Happens to Your Body on No Sleep