The feeling you get when you wake up on your day off work; on the weekend; or a public holiday as early as you would for work. Generally the alarm clock is off and there is no sound, but you still hear it for some annoying reason.
Of course you don't realise you can stay in bed all morning and for some moment feel like you never got any sleep at all.
Though, upon realisation (and falling back asleep) you feel better then if you woke up to your girlfriendfucking you. (well maybe not if shes good!)