u/Left_Run_1652

So my girlfriend and i came to Seoul with plans to spend a couple days in Busan for the weekend. About 2 days before I am checking for rail tickets and I can’t find anything. They are all sold out. Realizing we are not going to to be able to go we cancel our plans and stay in Seoul. Now I am checking the again out of curiosity and I find many more trains available. Am I high or something? Did I miss something here?