苦瓜怎知自己苦
[kŭ guā zĕn zhī zì jĭ kŭ]
'Ku Gua Zen Zhi Zi Ji Ku,' or 'how does a bitter melon know its own bitterness?' This somewhat humorous and profound statement can indicate self-awareness, referring to situations where one doesn't realize how difficult his/her situation is.