“Sleep is the interest we have to pay on the capital which is called in at death; and the higher the rate of interest and the more regularly it is paid, the further the date of redemption is postponed.”

— Arthur Schopenhauer

Here, in New York, where there’s a bravado culture — especially among lawyers and investment bankers — of who can survive on the least sleep, I’ve always felt a bit wimpy because I’ve always made sleep a priority and have even been known to take naps mid-afternoon. (Apparently some Tokyo-ites feel the same way.)

But now with a rash of articles about the dangers of sleep deprivation, I feel smugly vindicated.

The National Sleep Foundation recommends eight hours of sleep and if you’re getting less than that on a regular basis it will affect your:

1) physical health (digestive disorders, high blood pressure, weakened immune systems, weight gain)

2) mental functioning (ability to concentrate, multitask, pay attention, retain information, problem-solve, react quickly, and make good judgments) and, ultimately,

3) quality of life (you’re cranky, irritable, hyper-sensitive)

From a work standpoint, sleep deprivation threatens our ability to focus, the key element necessary to get into the flow. As  Ariana Huffington notes in her sleep challenge, “Work decisions, relationship challenges, any life situation that requires you to know your own mind — they all require the judgment, problem-solving and creativity that only a rested brain is capable of and are all handled best when you bring to them the creativity and judgment that are enhanced by sleep.”

If you constantly push yourself to get by on less you will never know what that peak performance — or flow state — feels like.