How does a duck know?

Today I got a 100 on my bio midterm, and I was so excited I decided to celebrate by changing my major to biology. It'd actually been in the works for a little while, but before taking the test I thought to myself, if I get a good grade, I'll take care of it. So after, high off academic excitement, I braved the long, 30 second walk to the advisement office, and now i have an appointment tomorrow to talk about my future. I could have just changed it without talking, but it seems like it's worth having a conversation when i'm changing the course of my whole life. Today's been really good actually. Turns out they made a small error on my chem midterm, so instead of a 95 like i thought i'd gotten, it was a hundred also. And the professor is going to add 6 points to the score, which averages my other midterm up to a hundred also. I haven't made straight A's since I was in middle school, it's pretty fun.