Sleep Nonstop Necessary?

[BohmaN]

A common conception (or misconception, I don't know yet), is that you should sleep the whole night through without waking up a single time since this would "disturb" your sleep. Well my question is: is it harmful for one to wake up in the middle of the night and then go back to sleep a minute later or will this have bad influence on you so that you will get more tired ? My mother always says that I must throw the cat outside before I go to bed so that the cat won't wake me up in the middle of the night and make me more tired next day. Is there any difference in waking up in the middle of a sleep stage compared to between two sleep stages? Reason why I'm asking is that I'm a bit concerned about WBTB... I hope you understand. Thanks for your answers!

[Bayside]

I feel more restored when I wake up in the middle of the night, and realize I still have a few more hours to sleep. I'm usually fresher and more alert throughout the rest of the day. There's nothing better than that feeling where you wake up, and feel like you have to go get ready for another crappy long day, and you roll over and see the alarm clock and realize you still have another 2 hours to sleep....