忘

过目不忘

guò mù bù wàng

to have a highly retentive memory

遗忘

yí wàng

to forget; to cease to think about (sb or sth) anymore

遗忘症

yí wàng zhèng

amnesia

难忘

nán wàng

unforgettable

健忘

jiàn wàng

forgetful

健忘症

jiàn wàng zhèng

amnesia

备忘录

bèi wàng lù

memorandum

公而忘私

gōng ér wàng sī

for the common good and forgetting personal interests (idiom); to behave altruistically

前事不忘，后事之师

qián shì bù wàng , hòu shì zhī shī

don't forget past events, they can guide you in future (idiom); benefit from past experience

勿忘国耻

wù wàng guó chǐ

Never forget national humiliation, refers to Mukden railway incident of 18th September 1931 九一八事變|九一八事变 and subsequent Japanese annexation of Manchuria

勿忘我

wù wàng wǒ

forget-me-not, genus Myosotis (botany)

吃水不忘挖井人

chī shuǐ bù wàng wā jǐng rén

see 吃水不忘掘井人[chi1 shui3 bu4 wang4 jue2 jing3 ren2]