If you're asking this question, then at least you may have some interest in learning Korean, which is a great start, or maybe you're just interesting in finding an answer to the question. Hopefully I will be able to answer both of these. If you're new to my blog or language learning, it may be worth reading through these three articles when you have finish this post:
There are a few glaringly obvious advantages and disadvantages to using Kpop and by extension music to learn a language. Advantages such as repetitive language, easy to listen repeatedly, enjoyable to listen to. Sadly a lot of these advantages are negated by any lack of effort to search the meaning of the words or effort to learn the language.
In my article 'The Role of Listening in Language Learning', I explain how listening plays two roles. The first to get sounds into your head regardless of whether you know the meaning or not and the second to act as a review to strengthen your memory of words you already know.
We all have movie lines stuck in our head, even ones from childhood. It's very common for humans to repetitively read, watch or listen to content they find enjoyable. There is a sense of comfort, especially for children, who you will find will want to watch the same movie every night or want you to read them the same story over and over.