Korean is very different from English (and Indonesian, and other languages, I suppose).
But a lot of people think that they can just “absorb” the language -like the way children learn a language- just by living in Korea for a couple of years.
And a lot of people have failed with that strategy.
They spent years in Korea, survived by knowing very little Korean, and came back to their home country barely able to speak Korean.
And they’re neither dumb nor uneducated people, some of them are college professors and even nuclear scientists.
I guess if you’re not that interested in learning Korean or if you don’t know about how to learn a language yourself, nothing can help you. Not even living in Korea for 5 years or more. Not even having a Korean spouse for 10 years or more.
In other words, if you’re really interested in learning Korean, and if you do know how you’re going to learn it, you don’t need to live in Korea, or have a Korean spouse, or have Korean friends, or have a teacher to master the language. Everything else, other than real interest and real effort to do the actual learning, is optional, not a necessity. ###