One of my college roommates, Scott, took a course called Thanatos - The Many Meanings of Death. Despite (or perhaps because of) the grim-sounding title, it was one of the most popular seminars offered through the University Honors program at College Park, and it's still offered. After class one day, Scott mentioned a comment the professor made: that the educational system teaches a sort of controlled obsession. I think the comment was more specific -- that technical education teaches controlled obsession -- but it was a passing comment five years ago, and I've forgotten that detail.

I have a stubborn streak in my own nature, and I'm fully capable of pondering a problem during most of my waking hours, and then having dreams about it at night. It can be consuming. I'm trying to understand some aspects of interface waves right now, and I awoke this morning to vague memories of a dream about wave interference patterns on the surface of a sea of fried onions. And while taking a tea break last night, I found myself idly tapping the table and watching the ripples spread across the surface of the tea in the pot -- and thinking whether I could estimate the wave velocity by tapping at the right frequency to set up a constructive interference pattern. I've also spent far too many hours so far this week trying to figure out my fluids homework, and it's likely that will show up in my dreams tonight, too.

Is that stubborn streak taught, or innate? Probably both. Is it constructive? Yes. Is it obsessive, with the unhealthy connotations that word carries? I don't think it is. Call it concentration, or perhaps stubbornness.

Call it time to think for half an hour more.

• Currently drinking: Water