溺海不知终老孤独不知天荒
[nì hăi bù zhī zhōng lăo gū dú bù zhī tiān huāng]
A dramatic way of expressing being so engrossed or drowned (‘溺海’ nì hǎi, submerged in sea) by emotion (usually love) that one doesn't know how time passes or feel loneliness, or even understand what endless means, emphasizing a state of being overwhelmed and unaware of external reality.