[lhorie]

Native speakers are often very forgiving about rustiness (even enthusiastic that you've taken the time to learn the language at all). I tend to think of rustiness as a function of how actually invested I am in the culture.

At this point, I suffer from the opposite problem: I've invested so much of my life into english (which is a second language for me) that I'm now losing vocabulary in my native tongue. I don't even regret it that much; language isn't really about the bragging rights, and how one feels about language shouldn't center around their ability to use it as a party trick IMHO. Instead, I think a healthier way to think about languages is to just see them as what they are: tools to communicate with the people around you. What you said about doing what's best in the moment is pretty spot on. Live in the moment, and let your language skills reflect from that.