"If you don't get good sleep, you're going to end up fat sick and stupid," says shut-eye guru Dr Robert Stickgold from Harvard University.
That's dire� but could it get any worse?
"If you don't sleep period for long enough you die."
And that's bad news for most us because Australians often complain today about being time poor and burning the candle at both ends.
"You can survive with very little sleep. You can survive on four hours a night but it's sort of like having chronic pain, you're always suffering from it," says Professor Stickgold.
The Professor is here for an international sleep conference and says lack of sleep is in epidemic proportions and is linked to the obesity problem.
"You can't get more sleep than you need," which probably explains why we're into the habit of sleeping in at weekends!
Dr. Stickgold says we're catching up on what we've lost during the week so how much should we be getting? Well ideally it's eight hours and 15 minutes.
Kids need a lot more than adults and here's the real good news, studies have proven a good night's rest also boosts memory.
"It's not a myth, we've done studies on memory. After a good night's sleep they'll be 15 or 20 % better at a task. If they get 6 hrs sleep, no better at all," says the Professor.
Dr. Stickgold says when in Rome do what the Romans do... taking a nap for an hour or two during the day.
"There's something magical about naps that we don't understand that they can be more efficient. As little as 7 mins of sleep in a nap can lead to improvement in memory an hour later.
"If the boss let you take a couple of 20 min power naps he'd get more work out of you," says the Professor.
Here's another tip.... give that morning coffee a wide berth.
"Reality is when you wake you should be wide awake and full of energy and ready to go."
But it's never to late to go to bed early, "�good news is you can get back into that effectiveness. The bad news is even with a single night of sleep deprivation, if you don't consolidate, it's too late."