school of hard knocks 艰苦的磨练
A：My boss is such a shrewd businessman everyone admires him.
B：Which university did he graduate from?
A：He never went to high school. He was educated in the school of hard knocks.
B：That’s incredible.
甲：我的老板是个非常精明的生意人，每个人都很欣赏他。
乙：他是从哪所大学毕业的？
甲：连高中都没上过。他是受了艰苦的磨练而成长起来的。
乙：真是难以置信。