What is so hard about learning Korean?

Recently, a man I met with to work on a new project, a man who has no previous experience with Korea, told me he’s going to start studying and learn Korean. I bit my tongue and said, “It’s really a difficult language.” I didn’t want to discourage him, but inwardly I’m thinking of all the “older” people I’ve known who have tried to learn Korean after the age of 40 and give up after a few months of trying. It’s axiomatic that children’s brains are adapted to language learning — American kids learn English, Korean kids learn Korean. Something happens in human brains as they grow older and it becomes harder to learn languages. My best student from 35 years of teaching over one thousand students thinks he learned Korean well because his brain “ossified” late. He was a “late bloomer." He says he simply understood Korean — he didn’t study grammar rules, didn’t memorize vocab lists but just learned it, like a child. Whatever theories there are for language learning, Korean is just a hard language. Why? Let me outline a few of many problem areas. First is pron