I've always been quiet a light sleeper, I think it comes from nearly always living in the countryside away from main roads and noise.
I remember being in my early teens and hearing glass smashing at about 4 in the morning. I was out of bed like a shot, straight into mum and dad, to give them a mild heart attack, before going down stairs with dad. Him in front me behind (not sure what I would have done).
"Sorry!" The milk man rather sheepishly said as he raised his hand. It took a while to go back to sleep after that!
I'm the same now, I have no problem falling a sleep and do so in a matter of minutes, but I'll wake up if a squirrel farts in the garden!
My wife is the polar opposite however.
Last night was a perfect example of that.
I woke up around four as it was blowing a gale and I could here something bashing around outside. I popped down stairs to see what it was (the meter cupboard door for the electric had come open) and then decided to just go outside and check nothing was blowing around in the extension (wellies and boxer shorts is a good look for a night time prowl in the snow!). I then went back upstairs and to the loo where I rather clumsily knocked a pack of tissues into the bath, it made a terrible racket, woke up the boy who then cried for 5 minutes before settling back down. I got back into bed and my wife hadn't even stirred!
Who else is a light sleeper?
Or who could sleep through an earthquake?
I think it's a good trait to have when you're looking after your little homestead though.