We all need it, but how we get it can vary from person to person.

Sleep. No matter how much we accomplish in a day, the body requires shuteye to recharge the battery. And while it's true that how much sleep varies from person to person (the stereotypical lazy teen seems like he needs 15 hours while the ambitious CEO runs on three), we all must get it to some degree.

And when the time comes to hop into bed, very few of us simply, well, hop into bed. We're routine oriented and that means there are simply some things we must do before we can sleep. The list of tasks can go on and on. Maybe they're traditional to-do items, like brushing teeth or flossing. Maybe they're OCD-related, like triple checking your alarm clock or placing your slippers exactly one foot away from the foot of your bed. Maybe they're downright odd, like humming the entirety of "In-A-Gadda-Da-Vida" or arranging your underwear by color.

The bottom line: we all have things we must do, quirky or otherwise, before we go to bed. So, fill in the blank for us. "I can't go to sleep unless _________."