I've always thought I had a built in clock (and that I'm not the only one). A few days ago I woke up thinking "it's 5:45", looked at my clock, and indeed it was 5:45. As I was sleeping so that I had to lift my body up to see the clock, and had a duvet cover (no duvet) completely over my head anyway, there's no way I could have seen the clock when I woke up.
People have built in alarm clocks, see [news.bbc.co.uk]

Doug Weller

Director The Hall of Ma'at
Doug's Skeptical Archaeology site::
[www.ramtops.co.uk]