Personally I think it's the damned internet and forums like these.
I used to be busy all the time when I was younger, either out exploring, riding the bike, breaking something that I shouldn't be messing with, fixing other things I should be.
Once the internet came along I spent more and more time on it, everything you ever needed to know is on here, yes it's funny at times, and on the whole you feel important as people reply to you.
Overall though there is a very overhanging feeling all the time that I JUST CAN'T BE ARSED to do anything else because its easy to sit here and type.
Very weird and it's chain I want to break!