This has been a painful lesson to me.

这是一种痛苦的疾病。

From my own experience, I draw a painful lesson HASTE MAKES WASTE.

从自己的经历中, 我得出一个痛苦的教训:欲速则不达.

This is the painful lesson of the individual, I hope my fellow countrymen, and take warning.

这是个人的惨痛教训, 希望同胞们引以为戒.

For China, the Siberian pipeline has disintegrated from a model of Beijing's new internationalism to a painful lesson in the complexities of the global oil market.

对中国来说，西伯利亚的输油管线在北京新国际主义模式中的土崩瓦解，是其在错综复杂的全球石油市场中的一个惨痛教训。