"I really gotta read up on that sometime."
"I've been meaning to review that subject."
"I'd really like to have at least a basic understanding of how that works."
These are things I catch myself and my peers saying all the time. I'm a grad student in the natural sciences and there's always more that I "should" know. Fundamentals. Specifics on a new research area. Some random thing I want to learn more about. But, where is the time?
Summer, that's where. You know how classes force you to learn stuff that if left to your own, you would never get around to studying? Yeah, that's useful. As much as we feel we're so above classes now, so much cooler than classes, that we learn everything we need to know when we need to know it for research, you have to admit that if it wasn't for the fact that you had to attend class to pass, you'd always have a list of other more important things to do that would prevent you from learning the subjects on your own.
Why it's Worth it to Know "Random" Things
Obviously, the things you need to know that are directly relevant to your primary research subject are taken care of when you are "working on research" (whatever that means). So let's not worry about that. What I'm talking about is classes that push your comfort level or broaden your base. Why are they useful? I have one simple answer: You won't be studying the same single, narrow, subject for the rest of your life. Surely you must have noticed how the brightest and wisest in your field seem to know the basics behind everything remotely related (the lucky ones observe this effect in their adviser). I whole-heartedly believe this characteristic is simply a result of having very strong fundamentals. They have reviewed the basics in their field multiple times throughout their life and now have that foundation to work on. Then, when expanding their research frontier, they feel less lost, they are able to look for help in the right places, and as a result they continue to push their own boundaries. They have exposed themselves to the basics of many different subjects throughout their career instead of always focusing on the narrow topic they are studying at any given time.
What class should I offer myself?
First of all, get your Leo Babatua on and offer yourself just 1 class to start. It can be easy to fall into the trap of "Oh I'm gonna learn about this, that, and that other thing!" and have a calendar so filled with scheduled classes you just skip all of them to do more important things throughout the week. Don't do that. Pick one thing you want to learn about but "haven't gotten around to" and offer yourself that class. The best place to start is a subject that is peripherally related to your primary research objective. That way your mind can't play the "you have more pressing things to do, when are you ever going to use this information?" game with you. Or at least, your mind has less of an argument if it tries.
What's the Class Schedule?
Whatever it is, make sure it's not heavy. That's the only rule. The goal is to make sure you attend class. That's it. Just show up, the learning then comes automatically I find 3 hours a week is good. MWF for one hour. Put it in your calendar and don't skip it! A strong recommendation is the morning because the deeper into the day you get, the more likely something will come up. Just walk in on MWF, spend an hour at class and then get on with your day. Try doing this without checking your email first. It's damn refreshing. It gets you in the mood of doing real work instead of pretending to do work by "processing" emails.
What IS the Class?
So what happens during class? Do you stand at a chalkboard and lecture to yourself? I don't, but by all means do whatever is necessary. Realistically, these self-classes almost always mean you, a book, paper and pen, and some peace and quiet. If you're in the sciences, do the problems or think of problems (related to your research is great) and do them to avoid getting caught in the blind note-taking and derivation trap where no information is processed. If you're in the humanities, check out Study Hacks for various note-taking and study tips to, again, avoid blind note-taking.
The point is to expand your horizons or widen your base of fundamentals. To do that, you need to simply dedicate the time to sitting down regularly and reading and the summer is a great time to do this. Let's end with some simple arithmetic that shows the power of repetitive behavior. Say you want to expose yourself to the first 3 chapters of a book called "Introduction to VeryImportantIdea". The first 3 chapters are 80 pages, which include non-trivial math and physics and some example problems scattered throughout. Say in one hour you can get through 5 pages at a pace that really lets you learn the material. You'll finish this class in a month and a half on the MWF 1 hour schedule suggested above. That means over the 3 month summer, you can fit in two of these classes. That means checking of two items on your mental list of "stuff I should know." Think about how many items you checked off of that list in the last three months. Give it a shot!