By far the best thing I have learned through language learning is that it is okay to make mistakes.
Up until the past Fall semester I wanted to get everything right, especially in language learning. I knew that I did not know everything, that is why I almost afraid to speak. That Fall Spanish class taught me to accept that I got something wrong, and the professor would correct me. In the past, I would have been horrified with this, but now I am accepting of it. This has helped my language learning tremendously.
I am not a very social person, and I used to hate speaking up in class. I still am working towards being completely comfortable speaking, but in some classes I do not care and even if I get the question wrong, even in an English speaking class, I do not really care. I have realized that I have to at least tried. A thought came to me in my English creative writing class last semester. We read and discussed some books, but I did not really say anything in the discussion. I then realized I am paying all this money for this class, I might as well participate. While I did not actually participate in that class, this semester I am actually volunteering to speak in class. In some cases I still get too nervous to speak, but I am working on it.
Overall, this is just another reason why everyone should learn a language. There is nothing better than realizing it is okay to be wrong, and to be corrected. As long as the person correcting you is sweet about it, and not sour.