píng shí bù zhǔn bèi shì dào lín tóu lín kě jué jǐng jié guǒ shǒu máng jiǎo luàn

平时不准备，事到临头临渴掘井，结果手忙脚乱。

If you don't prepare in advance and only seek help at the last minute, you end up in a fluster.