My internal alarm clock is pretty reliable when it comes to waking up on time for appointments and such. I mean, I have never failed to wake up early when necessary without the assistance of an alarm.
But boy, when I have nothing to wake up for, my body sure is quick to slam on that snooze button for a couple more hours. Though I feel ridiculously guilty if it's any later than 11am.
I feel guilty if I wake up BEFORE 11am if I have nothing to do But you are very lucky, I wish I was like that. I have a hard time getting up for work at 7:30am