I hated learning French in school. However, I can read a half decent amount of material in french now
I couldn't speak it or listen to someone speaking it and know what the hell they mean, but I can read it pretty decently. Erik Satie kicks ass.
My problem is vocabulary. I can learn basic grammar (enough to read the more complex sentences as well) very quickly, however, especially in a language such as Japanese, learning the vocabulary is a big stepping stone. In the case of Japanese, you have to deal with learning the kanji, as well as learning the pronunciation.
I don't live in the US, so Spanish is essentially as useless to me as Japanese or Russian would be, except of course, that I could find a lot of use for being fluent in Japanese, since the Japanese have a huge presence on the internet.
See, I learn differently than a lot of people, so simply being given a sentence in some language I barely know, that I can't read, and must simply assume the meaning has something to do with a flash card that I'm shown, generally doesn't help me very much.
Sure, I might eventually be able to figure out what it means by inferring meaning form the other cards, and eventually after that, being able to figure out the meaning and use of each part of the sentence, but being given some basic knowledge of the grammar and writing system would help me a lot more than simply doing that over and over.
I'm a bit of a social learner when it comes to language. I prefer having someone there to be able to ask my own questions and get clarification from than simply having to use a static resource, such as a book or online course to figure it out. If I can get a straight answer, I'll be able to learn it right away, because I know how to ask a question to figure things out.
The other problem with learning by yourself is that it's hard to find a properly ordered lesson that teaches you vocabulary well. Yes, classes in school are kinda boring when all you're learning is how to say cat and dog in that language, but learning sentences like "the cat is small" really helps cement your basic understanding of the fundamentals of the language. Building on that you can very quickly learn how to say things like "that at is looking at me" or "the cat ran away quickly". It gives you a solid foundation form which to build you knowledge.
Learning by yourself generally bypasses that part, unless you are able to teach yourself in a very structured manner, which I find quite difficult.
If I have a book on the language, I can learn the basic and intermediate aspects of grammar quickly, but I always get stuck very quickly on the vocabulary. Unfortunately, those programs and such that are supposed to immerse you in it and such just feel wrong when I try to use them. I'd much rather just try to have a discussion with someone and have the same sort of books that teachers tend to use for teaching resources in those classes.