SNU medicine

I want to try to apply for the specialty of human medicine at SNU, but I'm really confused. I heard that it's difficult and its environment is very competitive and it will often take most of the time. I won't find time to practice my hobbies or hang out with friends. As a person with a lot of hobbies, this makes me hesitate. Is there anyone to tell me his experience and if there is continuous pressure most of the days? Of course, I plan to take a year to study the language before starting and I have a background in medicine