Over the past few months, I've been fine but from around November I have been feeling sleepy any given time of the day. I first had this problem in August when I started staying up late to study (~12am) but I got used to that in few days. After that I've never had that problem uptil now. Only other difference in my schedule is that from November onwards, I haven't played outside very much or gone outside at all. I have no activity altogether apart from studying. I get 7 hours of sleep daily. Why am I always falling asleep?