My idea of a good time is a day spent taking notes, memorizing bits of information, and quizzing myself on what I've learned. For me, studying is tremendous fun.
A few months ago, I was about to start a big project, but I had a free day before it began. I thought about the ways I could spend it, and I decided what I would most enjoy was studying.
I decided to study some history and some French. I read about Louis XIV in Wikipedia - both in English and in French! I found a French podcast that consisted of a short story by Voltaire, read aloud. I logged new French vocabulary words.
It was great.
More recently, I've been enjoying math. Mostly, I'm reviewing high school algebra, but it's in preparation for the materials I never got to in school. I'd really like to learn calculus. In fact, I'd really like to read Euclid and Newton and understand what they wrote.
One of the things I especially love about learning now is the breadth of materials I can access easily. I have issues with Wikipedia, but I can't deny that it's an excellent starting point for most of the things I want to learn about - especially the geography behind my world history studies. Wikipedia has terrific maps of all kinds of places. By contrast, I have a disk-based version of the Encyclopedia Britannica on my computer, and its map resources are nearly useless. And when I wondered about the history of the naming of the Adriatic Sea, Wikipedia was the only resource I found with the answer.
But the resources for learning on the web go way beyond Wikipedia. For languages, there's literature at Project Gutenberg - sometimes including audio versions; the FSI courses; Wikipedia in other languages; and freely available streaming video of professionally produced telecourses from the Annenberg/CPB Project.
For learning science, there are introductory materials with great illustrations, amazing animations, more great streaming video from Annenberg/CPB, science blogs, and even freely available scientific journals (not to mention all the astounding materials at MIT's Open Courseware project and UC Berkeley).
I still love to play with my collection of textbooks - they've been great for math review (with answer keys in the back so I can check my work) and background reading.
My new favorite thing is flashcards. I've been experimenting with two programs, Anki and Genius, both of which track your learning and re-present each item at timed intervals designed to reinforce retention - items you know well will come up less often, and items you're struggling with will come up more. Initially, I was trying to decide which one was better. I've concluded that I want to use both: Genius is better for language study, since it requires you to type in the answer (so I can check my spelling), while Anki is great for reviewing concepts in science and history, since it simply shows you the answer and asks you to indicate how well you knew it. Anki also supports images and audio clips, so I'm looking forward to trying it out for art history and music history.
Of course, studying's much more fun if you don't have to do it. All my deadlines are self-imposed. I can switch directions any time I want. (I recently abandoned physics for biology.) I can be ambitious, or I can dabble - I can aim to simply identify five of the important components of a cell, or I can try to thoroughly understand them, know how they interact, and even learn the history of the scientific discoveries that led to the knowledge we have today.
It's wonderful to have the freedom to set my own pace and my own goals, and I just get giddy with delight when I get to spend a day simplifying equations, memorizing vocabulary words, and playing with flashcards.
Really - what could be more fun?