Is 18 Months Too Long to Learn Japanese?

In hindsight, the fact that my host mom spoke so highly of this guy, Kotsamoto, was probably a good thing for me because it gave me this really deep seated faith in his method. But I think part of the problem is also that if he had said, you know, 18 months to learn Japanese, even if you were quite interested, that's a long time. "You have to believe that it's possible"