Self Study and Language Immersion
Language, we already know, is best learned through immersion. Immersion generates assimilation. The best way I can describe what I know about immersion and assimilation is by comparing the information we receive about the new language with a stream of water, and the student with a sponge. Water will penetrate in the sponge and bath every room inside it. Now, our sponge will grow, and will keep growing without any boundaries.
Moving abroad and language learning
People who move to a country abroad can be classified in two different groups, when talking about language learning. The first group is composed by those who are eager to assimilate the new culture to some extent, while people from the second group always show very little interest in their new social environment, most likely longing the uses and ways of their native land. These attitudes mark the pace of progress on learning the new language.
The most important factor in learning and mastering a language
Motivation. Full stop.
Motivation is a powerful drive that makes us pursue goals regardless of obstacles or hindrances. The incarnation of motivation is the explorer moving towards a mountain top or an unchartered region. Motivation is a concept that makes no sense to motivated people, because it's a part of them. In a car dealership you wouldn't find a car without an engine, for such an object wouldn't be thought of as a car. A motivated person would not actually be able to explain what motivation is. As already said, motivation is integrated inside them.