Here are a couple more things to expect your brain to do in foreign language immersion.
Language headaches
You’ll probably get them! Speaking and processing a new language, in a new environment and in daily situations can get extremely stressful and fatiguing. A lot of people complain that once a day during the first few months, they will get killer headaches, along with grouchiness and minor exhaustion once a day or so, just from dealing with a foreign language nonstop. Mine would come around 3:00 p.m. Don’t let these discourage you. Take a nap, or find some time to completely relax, if you can, and you should be fresh again in a few minutes. For a while, you may want to figure out a relaxation schedule for dealing with this problem. If you start having this kind of trouble, don’t worry too much. It will pass as you adapt more and more. This kind of stress can come at parties sometimes too, and if it’s possible, and no one will be offended, it helps to move to a quiet place for a while (maybe walk up and down the street for a few minutes), so that you can clear your head and get your energy back.
Drifting in and out
As you reach the point where you have begun to communicate a bit, and can actually understand something and contribute to the discussion at the dinner table, in the pub or at group gatherings, you may find your mind blipping in and out of the conversation periodically. You’ll be doing okay, but suddenly the conversation starts to overload your mind, and you’re on a different planet. After a couple minutes of mental absence, you’ll start drifting back, only to find yourself gagging on language input again and then wafting off for a while more. This might happen to you several times in the space of only 15 minutes or so.
One important thing to remember is that in any group conversation, even in your own language, your attention is likely to lapse from time to time. Few people, if any, are always 100% on top of whatever they’re hearing. A teacher who is unusually full of bull, or a corporate manager who speaks mostly in buzzwords can strain our receptiveness almost as much as people speaking a foreign language, so don’t let the problem worry you too much as you acquire your new tongue. Push yourself really hard to keep on top of things, but if your mind just has to go bye-bye for a while, then let it depart. Just make sure you stay at the door to greet it the second it’s ready to come back.