Nothing is more critical to your health than getting a good night's sleep as much as possible. There are some tough guys out there claim they don't need to lay their heads on their fluffy pillows for more than 4-6 hours, but they're just pulling your leg. If you really want to function at your highest level, you can't do that on like 5 hours of sleep, no matter how many cups of coffee you drink to make up for it.
Sometimes, sleeping 8 hours isn't even enough! Some people take two naps a day as grown adults! I respect anyone who is so devoted to sleeping that they build it into the waking hours, but in no way could that be me. I like being awake just as much as being asleep, if not more. If you're in the mood to lie down, these sleep memes will be like melatonin.