Here are some reasons why I finally restarted learning Chinese even though I am not yet fluent in Japanese.
I started last year, after passing the 3 year mark in Japan. I felt that I still had a ways to go in Japanese, and since I will be here forever, I have plenty of time to get there. And when I do get there, it won't be any astonishing feat. If I could have learned Japanese in less than 3 years, then that would have been great. But since it's going to take me 10 years, I might as well get started on something else.
I didn't know any good materials or methods for learning Japanese. All I can find are some textbooks. So I could see the end was nowhere in sight. I felt I might as well move on because Chinese is going to take a lot of time too.
I found a good learning Chinese podcast. And then there was FSI Chinese online. So I thought I could get started with some free materials.
Actually, I had planned to do Korean before Chinese. But since all the Chinese materials appeared, I just launched into Chinese.
I bought Assimil Chinese with Ease and started on it in December (2006) after the JLPT. I have now worked with my Assimil course for 157 hours. I cut the spaces and pauses out of the audio and I just listen to the dialogue. My objective is to listen to every dialogue 1,000 times. I estimate about 500 more hours to do that. I am currently through lesson 64.
I guess I'm in no rush. It's not like I'm going to China or anything. So I'm going to overlearn the Assimil lessons and use that as my foundation to build upon. By the time the Chinese language really does become globally important, I'll be one of the people who can understand it.