I actually made a bit of an effort to scrape the rust off my Chinese recently, the first time I've really bothered in 7 or 8 years.
And curiously enough, it happened while I was out of the country (and on the brink of quitting the damn place for good!).
It may just have been a case of being on holiday, having time on my hands. But I have time on my hands NOW, and I am finding it difficult to continue to apply myself to Chinese studies here.
I have a 'teach yourself' type self-study book given to me by a friend years ago, some time before I even moved to China. I have several times tried to work my way through it, but I've never got to the end. In fact, I think I've only once got much more than half-way. Time and again I break down about a quarter of the way into it.
Perhaps it's just not a very good book. Though I think it is; I've dipped into several other similar textbooks, and this one appears to be the pick of the crop.
Perhaps it's just that my motivation is stymied whenever I'm in China, and I am being constantly reminded of how little day-to-day utility there is in trying to speak the language (not to mention being constantly irritated by foreigners here tiresomely showing off the little bit of Chinese they know, when there's no real need for it).
And then again, perhaps it's just a matter of habit: I've never bothered to study Chinese while living here, but I have studied it intermittently in the UK. However, I am usually quite good at taking conscious control of my habits and modifying them. If I can give up drinking (such a central part of my life!), surely I ought to be able to cultivate a regular study-and-practise habit with learning a language.
I think it's primarily a matter of reaching a practical threshold of language competence with which you're comfortable. I've always been curious about whether I might be able to learn a little more Chinese, and whether this might markedly change my experience of the country; and, after a couple of months or more away, I was starting to fret about perhaps having forgotten all the Chinese I ever knew. So, I started dabbling with a bit of self-study again. But I reached that point about 4 or 5 chapters in (as I have so often in the past) where it just started seeming unreasonably difficult - and I couldn't find sufficient motivation to continue. The reason why it gets hard at this point is that the first 4 chapters are basically the Chinese I know. And the reason why this is all the Chinese I know is that this is all the Chinese I've ever seemed to need to know, for basic survival. And that, for whatever reasons (that might be another post or two on its own), is all the Chinese I've ever wanted to know.