Very true. Although, there is a slight possibility you are getting too much sleep... I know this occasionally happens to me when I get 11-12 hrs of sleep on weekends - I'll feel much worse than had I gotten up an hour or two earlier. However, this will depend on your age a bit too (I'm not a doctor, but I'm pretty sure when you're growing, you need more sleep ). I want to say that your diet could also affect this too; however I'm not quite knowledgable in that subject, so I'll let anyone else who feels like it touch that base. Just my thoughts.