I've decided to take the PDE sequence this year. I've intended to take Math 222A-B every year since I came to Berkeley, but I always ended up deciding another course or activity was more important. But now I'm registered for the class, and I have the book. I'm looking forward to my classes this semester, both in partial differential equations and in fluid mechanics. I'm past my required coursework, but I want to learn the material. Besides, there is something relaxing about mathematical classwork. Perhaps it's that homework problems tend to have answers that are shorter, neater, and easier than the answers to problems that arise in my research. Or perhaps it's just the change of pace.

The semester has officially commenced, though instruction doesn't begin until next week. The undergraduate population has returned to campus, along with the fraction of the graduate student population that spent the summer at an internship and those just arriving. It's quite a change from the summer campus: now, the majority of the people I see when wandering out of the office are not staff, graduate students, faculty, deranged, or some combination thereof. Of course, I only see the difference when I wander out of the office and pay attention to the world around me.

The start of the semester also means the return of free food. I ate a dinner of leftover noodles, rice, and tofu from some activity or the other. Now I have the energy to sit in my office and work on this problem again for hours!

Time to head home, I think.