OK. For the past year maybe I've been waking up in the middle of the night ONLY one time. I go to sleep at around 11-11:30 pm and wake up at around 7:30-8 AM in the morning. BUT! I tend to wake up only once every night. I usually fall asleep 5 to 10 minutes after waking up. And when I go back to sleep, my sleep is completely uninterrupted till morning. I seriously don't know what the deal is here. And the main key word is 'once'. Not twice or thrice, only once.