Because the weekend is here! (Although I'll be on call)
And because it's a joyful feeling to fit into clothes that you thought were doomed for the donate pile. It's made even sweeter when there really wasn't a concious effort to try and slim down.
These pants are almost 6 years old - I remember I bought them at the Banana Republic outlet in Ohio, when I was still trying to look for a job, fresh out of college. In those days, BR was, to me, high end.
It's nice to be able to fit in them once more and remember all the hopes and dreams that one tends to have as a fresh-faced young adult.