[shivsta]

#3 is not exactly correct. Young people should sleep 9 hours a day whether or not it feels like you 'need' the sleep. Many people will feel fine after 6-7 hours of sleep in the morning, but studies have shown that even if you feel rested you will not perform as well on cognitive tasks if you do not get 9 hours.

I got hung up on the details.

[ejcx]

I think your comment is characterizing exactly what I say not to do, even if you might be right.

My comment is about staying healthy over the duration of your life. It's also about doing what you can and not sweating the small stuff. Studying hard and sleeping 6 hours will get you better test results than sleeping 9 hours and not studying. Your comment is splitting hairs about a small increase and missing the point....