I guess you interest in Japan might disappear in that 4 years. Same happened to me. Be careful not to be too enthusiastic or you might lose your interest.
yeh, trust me on this one, dont be too enthusistic about Japan else you will lose motivation quickly
I think these two posts are way off base. I don't think there's anything inherently wrong with enthusiasm, or that you have to "be careful" of having "too much" of it. The problem comes when a person's enthusiasm is poorly-directed and/or unrealistic. They're attracted to some idealistic image of Japan that has little, if any, basis in reality. They spin their wheels for a while trying to learn the language, but don't make much progress, and then realize that there are other things more important to them.
I don't think there's anything really wrong with this though. If Japan and Japanese is really important to a person, they'll probably find a way to make things happen. If not, and they move on to other things -- so be it. That was probably the better choice for them to begin with, so it's all for the better.
One hint: if you find yourself having to ask yourself, "Is (...) really
that important to me?" over and over again, then you probably already know the answer.
This goes for a lot more than just Japanese.