ideal sleeping hours

I've read an article from yahoo talking about the How much Sleep is Ideal.

And i was intrigued with what it revealed. It says that people who sleep between 6.5 hours and 7.5 hours a night live the longest. And those who sleep 8 hours or more, or less than 6.5 hours, don't live quite as long. waaaaaaaaaaaaaa.... well fortunately for the past few months and even last year i slept around more than 6.5 hours daily. ehehehehehe i usually sleep at 12 midnight and woke up at 7 in the morning. Guess i'll gonna live longer than i thought. The article also mentioned that there is just as much risk associated with sleeping too long as with sleeping too short. The big surprise is that long sleep seems to start at 8 hours. Sleeping 8.5 hours might really be a little worse than sleeping 5 hours. whoa! I couldn't believe that sleeping longer that 8 hours would lead to sickness that would lead to many illnesses. For the details please click here.