I believe that the reason is obvious.


Anyway, I find this occasion a good chance to introduce my watchers a version of ‘Happy Birthday to You’ sung in Korea;

왜 태어났니?
왜 태어났니?
엄마 실수 아빠 실수,
왜 태어났니?

Sometimes, the third line changes to,

사람도 많은데,


It is my favorite birthday song, though I don’t sing it for others. I can also tell you that this is probably not the version appropriate for children.