ok, so lately I've been getting to bed at around 3 or 4 in the morning, and waking up around noon. the thing is, I'm getting just as much sleep as when I went to bed at 11 and woke up at 6:30, (ish), but I feel like crap when I wake up around noon. what gives? why am I groggier on the shifted sleep clock? and does this happen to anyone else?

I actually feel better when I can get up that late or later but sadly I have to get up before 6 AM to get to work. Of course I don't ever really sleep all the way through either because I never can unless I'm sick or so totally wasted. The dogs will usually get me up a couple times to go pee too.

Maybe because you're more tired when you slept at 3am, than when you slept at 11pm. I think our state just before going to sleep has an impact on the type of sleep we'll have and the waking too.

It also could be that your Over Sleeping. you should try and be really tired and just go to bed earlier. That happens to me where If I stay up a couple of nights really late, and I get up the next morning I'm really groggy. I've been an early riser all my life,and there are still days where i have to literally roll out of bed to get up.

why do you go to bed so late/sleep so late? humans aren't meant to sleep during the day, maybe that's why you feel groggy.

I was told by a friend that the earlier one goes to bed the better he/she will feel when they get up. That there's a difference between going to bed at 9.30pm and waking at 5.30pm (waking up feeling refreshed) than going to bed at 3am and sleeping the same amount of hours (waking up groggily).

I agree that we aren't meant to sleep during the day and that can lead to grogginess. Also over sleeping can too, and things like sleeping with the TV on and what not can make you more tired... or you could possibly have sleep apnea..

Why so groggy??? well your body has an internal clock that needs to be followed to the point. This is with eating, sleeping, activity, etc. If you go to bed when body tells you it is time and wake up about 8 1/2 hours later. Your body will rest and recharge to its max efficiency. Of course 8 1/2 hours of sleep and times to sleep will differ from person to person. Some people will actually sleep better during the day and work better at nights/graves. They are far and few but they do exist. I am a health major at school so there you go.

Yeah, I have the same problem. I'd say probably because we feel like we've wasted half the day. Also something that happens to me is that the rest of the world is up and kicking at 8 or 9, when they start making noise. Whether its some guy mowing his lawn or my mom walking in the room directly above mine, I'm sleeping a lot less deeply. I might not actually wake up to every noise, but I'm a lot more awake. So yeah, that's my explanation for it.

I always feel mega tired when I go to sleep at the early hours of the morning and wake up in the afternoon. I find I could sleep for a lot longer when I do that. I force myself to get up though.