I'm back in Tokyo after quite an interesting week in Silicon Valley. As I landed in the airport, I noticed that the "gee, I'm back in Japan" feeling that I usually have was much less. The airport smell was "normal" and I didn't feel I was really "back" but that it was just another normal day. I think it is because I have been traveling SO much these last few months. So here is my theory.
I think that when you SWITCH infrequently, there is a literal switch. I remember when I used to only travel once or twice a year, I could feel my brain switch from English to Japanese, driving on the right side of the road to driving on the left side of the road. When I started traveling a lot more, this switch didn't happen and it all became one experience.
I've noticed that people who I went to school with at the American School in Japan can generally mix English and Japanese, but many people who switch between English and Japanese can't mix. (We call this mixing chanpon)
Having just switched to the Mac, I'm finding a similar experience. I now have 4 different keyboards and 3 operating systems (Mac, OS X shell, Windows) each with their hotkeys. I find that as I switch back and forth between keyboards and OS's a lot, I am becoming more and more able to "speak" the different hotkey combinations without messing them up.
I've heard that people who learn a third language after learning a second language often use words from the second language by mistake. I'm sure this is because your brain is trying to "map" the new language on in the same space as the old one and you trigger the wrong thing sometimes. It's like trying to install a new OS over an old one and keep some of the stuff from the old one.
I once took a class on brain damage. There was a study that we read that talked about "brain crowding". Some girl was a great at drawing and got brain damage and she lost her ability to speak. As she learned to speak again, her drawing ability diminished. So the brain reallocated that part of the brain towards to more a important thing.
Assuming that you have a limited brain surface area, I guess the trick is storing things as efficiently as possible.
So my theory. When you are switching between modes and you hear a big CLICK in your head, you're probably using two different sections of your brain. When you can get it all to feel like one thing, you're probably learning to store it in one place and trigger just the differences and that method, I assume it's more efficient, but I wonder if it is worth trying to get better at this sort of multi-mode storage. I wonder if you can LEARN to learn more multi-modally... hmm....