WHY AM I SLEEPING SO WELL?

Many of my contemporaries are complaining that their nightly sleep is too short.
Every night, I am firmly asleep well before 2100 hrs. And, it stays that way for 9-10 hours; with a short break when my cat wakes me up to have his midnight snack. (cats like to eat a little, or much, if you allow them, every 6 hours!)
BBC Discovery, or rather Prof. Russel Foster, has an interesting, possible answer, that has to do with how the body clock can be influenced by replacing old nuclear cataract eye-lenses with plastic ones. I got that done more that 5 years ago.
Want to know more?:
http://www.bbc.co.uk/programmes/p002w557