If your waking up to an alarm clock your not getting enough sleep. Yes, that sounds ridiculous, but so did eating a side of broccoli when you were 12. The people who are telling you to get 8 hours of sleep are the same ones who say “eat 10 servings of bread a day”, these are not words of wisdom. Ideally you would sleep when its dark out, and further, coordinate with the seasonal changes and day/night ratio. You would be sleeping much more, some 10-12 hours a day, in the winter. And when it came time for summer, you’d put your party hat on. Now, I know people will stop listening to me if I tell them to get 12 hours of sleep, so let’s split the difference. Get 9.5 hours of sleep.
Before man invented artificial light (the light bulb and before that, fire) humans were sheltered in their cozy caves by nightfall, and if they weren’t then they were getting mauled by lions, tigers, and bears (oh my!). Man followed a circadian rythm like every other living entity on the planet. By introducing artificial light we have extended our awake time some 30-50% beyond what we were designed to handle, depending of course on how late you stay up. For more reasons than I care to write about, going rogue and running your engine 50% longer than it’s supposed to be run is going to lead to problems. Instead of more oil changes, you get things like radiation therapy and stents.
If you are getting less than 8 hours of sleep, your killing yourself. If your getting 8 hours of sleep, you can do better. Go to bed earlier!