That is very true. I speak 4 languages all of which I have learned by moving to other countries and interacting with people. When I was 9 and we moved to Franc

That is very true. I speak 4 languages all of which I have learned by moving to other countries and interacting with people. When I was 9 and we moved to France I had almost 0 understanding of French. I went to a "school for foreigner" and in two months switched to a classic French primary school. Literally, I learned enough French to fluently communicate with my classmates in two months. In contrast I was trying to learn German for four years by taking lessons. Without much success. After those 4 years I was able to speak enough of it, but I didn't feel comfortable with the language. What's worse, I was not forced to speak German with anyone (as I was with French). Two years later I barely remember anything. You need to be forced to do it. Practicing alone will not help much; you need to use the language in order to know it. If you really want to learn Japanese, which I think is quite hard, move there for a few months and get involved with the community. Maybe get a job, join as many groups as you possibly can. Speak, write in Japan (maybe start a blog in Japanese once you know the basics). And go there alone, this way you are not tempted to speak English or Spanish.