inscribe a debt of gratitude on one 's mind
It is hard to forget.
Idioms and allusions
Source: the 96th chapter of Xu Zhonglin's Fengshen romance in Ming Dynasty: "my concubines are deeply loved by your majesty. They are unforgettable."
Discrimination of words
Synonym: Unforgettable usage: as predicate and attribute; metaphor: painstaking thinking
Chinese PinYin : lòu xīn kè gǔ
inscribe a debt of gratitude on one 's mind
Dethrone extravagance and advocate thrift. chù shē chóng jiǎn
be under attack from all directions. sì miàn shòu dí