That was an example but it could be woo.
Go down a level and find a class or collaboration group on the object level thing you want to do.
That's not realistic advice. You can't simply take a single class because you're interested in it, if you do so you have to take the whole time-consuming package of other classes that you may or may not be interested in, the class could be another year. Usually you do it because of pressure or you have to take the chance that the credentials are useful for something.
There are specific exceptions, one that I know is foreign language. I know people who've been 4 years on foreign language courses and haven't learned it. I suggest reading an actual book written in that language then looking up what you don't know. I know this works because I tried it, not that taking one semester of class first isn't good. But nope, maybe another class is better. Hmmm.
SolveIt: In the very thread there is someone who confuses this and you say, "My post was about classes, not "self-improvement communities". I'm very skeptical about the latter."
I'm not contesting that learning is improving but there is a class of things that people call self-improvement like "how do I not procrastinate". There is a common term for lone-wolf learning which is "self-learning". Not every improvement is learning either, what if you do a workout? If there are already two common terms why switch them? But then, when I was introduced to LW I saw a post mentioning "literal wireheads". Hmm.
But if you are simply talking about learning things by reading a book from home (vs a class setting where the professor barely explains the subject matter, rants about unrelated stuff for an hour then asks you to learn by reading a book from home and this is "motivating"), you can do it just fine. If you want to socialize, there are other ways to do so.
Title is misleading, I thought you were going to talk about self-improvement in general for which this was an interesting statement but it's about academic learning so why not "against lone-wolf learning"? What you said is both, (1) already consensus pretty much everywhere, everyone thinks taking classes is best, it's improbable that even someone from LW isn't aware of this viewpoint (2) clearly wrong, but not something I feel discussing and I'm only replying to complain that I was click-baited into reading this.
Has anyone considered that life may not be that great? Considering that:
I don't get the problem here.
A murderer is bad. A non-murderer is neutral. Some guy is good. A martyr is gooder.
Somehow he takes this and utilitarianism to mean that everyone is evil, a non-sequitur. Then he blames the bystander for deaths that don't even have a cause-effect connection to him.
Edit: the ultimate truth is too much for mortals to behold.
It seems a stretch to put Buddhism in the category of don't-really-care-about-Being. Rather, it's an important point that there is no being and realizing so brings countless bliss and enlightenment.
ISIS is led by a cabal of wizards. The destruction they caused feeds into a spell designed by smart, rational magicians to create the Philosopher's Stone.
I'm talking about classes where teachers cover the topics and occasionally there are movies. Even in a class like this, the success rate of it is low, unless one has real experience on their own (self-learning by books, traveling abroad to where they speak that language). Reading a book in class and outside cannot be compared. The teacher has to specifically assign a "book-reading" class then read out loud for a class (that will cover... a single chapter per lecture?) and the material they choose is usually something artificial they made for the course... it's not comparable. You say these classes are effective. I don't believe you.