Tae Kim's Blog and has specifically to do with learning the Japanese Language, I think the idea applies to pretty much anything challenging we might try to learn. To read the whole thing, click here.
I started learning Japanese as an adult (college sophomore) and became proficient in about 5 years (full story here). So I’d like to think I know the various phases you go through when learning a foreign language. There are different things to watch out in each phase so let’s look at the long journey and how to successfully reach the end of the rainbow to find the pot of gold. Unfortunately, in real life, a rainbow is completely round so there is actually no end so good luck with that. Ha ha.
There are roughly 4 stages of language acquisition: excitement, depression, laziness, and acceptance. The excited stage is when everything is new and you feel a tremendous amount of progress everyday as you learn words like “to do”. Following that is depression upon realizing that no matter how much you learn, it’s still not enough. After you reach a certain level, you then become lazy because you can get by most of the time with what you know. If you overcome the lazy stage, the final stage is acceptance as you become resigned to the fact that learning a language has no end. You try the best you can and keep learning for as long as you use the language.