Though I had my seven hours of sleep, I dreamt about alot of things all night right till my alarm clock rang this morning. I can't remember any of them but I woke up feeling groggy and tired. Now I'm nodding off at my desk at 10am in the morning!
I guess that's what they mean when they say it's important to have quality sleep. Last night's sleep was probably of inferior quality. I was too busy dreaming.