Many people tend to forget this and it often ends up costing them the hunger for more.
One simple example is the amount of people learning Japanese only for the Manga. There is a probability that your love for the language disappears if you go for University classes and ignore the classes about Japanese culture and history. A friend who studied Japanese in University told me that they started with more than 130 people but finished the degree at only 20–30.
Furthermore, the culture obviously impacts the way people act and speak. For this reason, when starting to speak it, you must adapt your way of talking.
Western languages are based on an individualist culture, many Asian languages are based on a collectivist one. This means that stating an opinion in French or German would be more straight forward compared to stating one in Korean or Chinese for instance.
The more you practice, the more natural it gets, but this also means that the language and culture start to be a part of you. It implies that those are becoming second nature to you and that a “Second You” starts appearing.
This “Second You” adds to your original personality. As time passes by, the shocks between your two personalities merges into a new one that takes over your life.
I used to be a rather straight forward person enjoying my family but never really showing it nor spending much time for it. However, Japanese and Korean cultures put an incentive on the family while also avoid giving strong straight opinions. For this reason, despite the distance, I take and give more news to my family and my opinions are put forth in a less strong way.
Obviously, the more languages, you become a melting pot on your own. Cultures clash, debates in your head sometimes make no sense, you end up not knowing how to express yourself the proper way in X or Y language as sentence structures diverge too much in your head.
It is then that you should take a hard look at yourself in the mirror and make the difficult choices of choosing who you want to be.
Absorbing a new language and culture does not mean you need to forget your own. If some new aspects do not fit who you believe you are, you need to realize it and either willingly decide to ignore those, or go around them.
These differences and evolution are really put to the test in multi-cultural relationships. Indeed, an intimate relationship means that the two people are in harmony. Whether it is better to be similar or different is a whole other topic, but when coming from various cultures, some aspects held dear by one may be in strict contrast with what the other believes.
Of course, this is not to say that multi-cultural relationships cannot work. It means that the culture clashes that you experience within yourself may start appearing a lot more outside of yourself and without leaving you the time to weigh the pros and cons. Thus sometimes leading to stating opinions you’d regret later on.
To sum up, you must know and understand that everything we do makes us change. Learning a language does as well. The only difference is that the change occurs hidden in the back. Little by little, most of the time without realizing it, your personality will change. Be aware of the culture associated with the language you learn. Because nothing feels more like a waste of time than learning a language and realizing we don’t like the country and culture in the end.