If I now only had something to do besides study, this would be a perfect day

Since I woke up (at 4:30) I've been in an incredibly good mood. Though I'm normally a pretty happy person, I tend to grumble about things like waking up this early when I could have slept till 7. But not today. I got up and went out with the dog - slipping on the ice, which would also result in some complaining on any given day. I was still content after I sat through the first half of one of the most boring lectures on animal nutrition I've ever heard (it's Saturday, students are not supposed to accept being at uni on Saturday without complaint). Since then I read and went to the cinema (Mona Lisa Smile not bad) and I'm still smiling. I'm even looking at my books, thinking about getting a start on microbiology or meat hygiene.
This is a very Strange Behaviour.

I suspect it's something in the water.