Only I Didn't Know is the title track of IU's first single album Real+, which is the follow-up to her third E.P, Real.
[Verse 1]
정말 넌 다 잊었더라
Jeongmal neon da ijoeotdeora
You really forgot everything
반갑게 날 보는 너의 얼굴 보니
Bangapge nal boneun neoui eolgul boni
When I see your welcoming face
그제야 어렴풋이 아파오더라
Geujeya eoryeompushi apaodeora
Then I started feeling vaguely hurt
새 살 차오르지 못한 상처가
Sae sal chaoreuji mothan sangcheoga
A wound that can't heal itself
[Pre-Chorus]
눈물은 흐르질 않더라
Nunmureun heureujil anteora
My tears wouldn't flow
이별이라 하는 게 대단치도 못해서
Ibyeorira haneun ge daedanchido mothaeseo
Breaking up wasn't even a big deal
이렇게 보잘것없어서
Ireoke bojalgeo seobseoseo
Because it's worthless
[Chorus]
좋은 이별이란 거,
Joheun ibyeoriran geo,
A pleasant goodbye
결국 세상엔 없는 일이라는 걸
Gyeolguk sesangen eomneun iriraneun geol
Ultimately there can be no such thing
알았다면 그때 차라리 다 울어둘 걸
Aratdamyeon geuttae charari da ureoldul geol
If I knew I would have cried it all out then
그때 이미 나라는 건 네겐 끝이었다는 건
Geuttae imi naraneun geon negen kkeuchieot daneun geon
나만 몰랐었던 이야기
Naman mollaesseotdeon iyagi
A story only I didn't know
[Verse 2]
사랑은 아니었더라
Sarangeun anieotdeora
It wasn't love
내 곁에 머물던 시간이었을 뿐
Nae gyeote meomuldeon shiganieosseul ppun
It was just time spent next to you
이제야 어렴풋이 알 것만 같아
Ijeya eoryeompushi al geotman gata
Now I think I know what it feels to be vaguely hurt
왜 넌 미안했어야만 했는지
Wae neon mianhaesseo yaman haenneunji
[Pre-Chorus]
내가 너무 들떴었나 봐
Naega neomu deultteosseonna bwa
Maybe I was too excited
떠나는 순간마저 기대를 했었다니
Tteonaneun sunganmajeo gidaereul haesseotdani
You anticipated the moment you would leave
얼마나 우스웠던 거니
Eolmana ooseuwotdeon geoni
How amusing was it for you?
[Chorus]
좋은 이별이란 거,
Joheun ibyeoriran geo,
A pleasant goodbye
결국 세상엔 없는 일이라는 걸
Gyeolguk sesangen eomneun iriraneun geol
Ultimately there can be no such thing
알았다면 그때 차라리 다 울어둘 걸
Aratdamyeon geuttae charari da ureoldul geol
If I knew I would have cried it all out then
그때 이미 나라는 건 네겐 끝이었다는 건
Geuttae imi naraneun geon negen kkeuchieot daneun geon
By then you were done with me
나만 몰랐었던 이야기
Naman mollaesseotdeon iyagi
A story only I didn't know