If Mariah Carey acts a little strange sometimes, it may be because she's chronically sleep deprived. The popstress told The Sun newspaper she usually manages only three hours a night. "I stay up thinking about all the loose ends," she shares. "When I get these flashes of nerves, I'll call a friend, watch a movie or sit in the kitchen with my dog and cat. To which we can only reply, "Zzzzzzzzzz."