The weekend before the semester started, I was still tinkering with the latest Disqus code put together by fooleap. Things immediately got messy: the PHP version on my server was too old for the new features to work, so I contacted the hosting provider and moved to a plan with a newer version. After that, a different problem showed up—the Disqus API wouldn’t connect. Then Monday arrived, the new semester began, and everything suddenly exploded into full-speed chaos. I had no time at all to keep debugging the API, which means the comment list still won’t load properly from inside the firewall. What a waste for an otherwise good commenting system.
This semester I only have two courses, but one of them is the required Mechanics of Solids. The amount of material covered in class is not especially large, but the homework definitely is. So far we’ve only been working through fairly basic index notation, yet the assignments already involve a lot of mathematical derivations and proof-based problems. There are more than ten major assignments in total, and the first deadlines are only about two weeks away. That pressure showed up fast.
On top of that, I have a habit of rewriting my class notes after lecture whenever the original pages look too messy. Part of it is probably obsessive-compulsive tendency, but reorganizing everything neatly also helps me remember the material better. Of course, that takes time too. With all of that combined, this week has felt tightly packed from start to finish. Luckily the other course is relatively light, so I’m still managing.
For more systematic note-taking, I had already been gradually moving over to digital notes some time ago. They’re easier to carry around, automatically backed up to the cloud, and available whenever I need to look something up. It really is convenient. On the hardware side, I’m using an iPad Pro with an Apple Pencil. I can’t claim I’ve compared every option out there, but this setup feels good to use, and that matters most.
As for software, after reading plenty of people’s experiences online, I ended up choosing GoodNotes. It can sync data across devices with iCloud, and you can also back everything up to cloud storage. Notes written on the iPad can be viewed seamlessly in GoodNotes on the Mac as well, though there still isn’t a Windows version. The biggest selling point seems to be handwriting recognition and search. Being able to search handwritten notes later is incredibly useful.
Most of the homework for this course is made up of derivations and proofs, so the amount of scratch paper and pen refills I’ve been burning through has multiplied compared with before. It honestly brings back memories of the period right before the college entrance exam. The worst part is getting to the end of a problem and realizing you still can’t solve it. Because of that, I’ve spent several nights this week working on assignments until around 11:30 p.m., and the result has been a pounding head the next day.
Even so, I genuinely like this course so far. A lot of what it covers is useful, and it’s filling in major gaps in my background. Take the 梯度算子（gradient operator）, for example. Only now, with this instructor’s explanation, do I finally understand what is actually going on in the calculations.
That also reminds me of a field theory class I had back in university. The most important foundational concepts in that course were all kinds of differential operators. In mathematical analysis, those ideas had only been mentioned briefly—they were never really treated as a major topic—so we were all hoping the field theory course would finally make them clear. Instead, the professor opened with: you already learned this in mathematical analysis, so I’m not going to explain it; go read the book and do the exercises yourselves. Seriously? I understand the value of independent learning, but skipping the core content of the course and pushing it entirely onto the students is something else entirely. At the time I more or less fumbled my way into using those operators computationally, but the actual reasoning behind them always stayed vague to me, and I never really figured it out afterward either.
Until now.
This course feels like someone finally opened the door to a whole new room. That also explains why I’m taking this material and these notes so seriously. I know this is foundational knowledge in the truest sense—basic, essential, and something I need to understand solidly.
There are still two months left in the course, and honestly, I’m ready to throw myself into it.