北宋的司马光，从小就聪明好学。
Sima Guang of the Northern Song was bright and studious from childhood.
他常说：“时间如流水，一去不复返。”
He often said, “Time is like flowing water; once gone, it never returns.”
为了多读些书，他常常废寝忘食。
To read more, he frequently forgot to eat and sleep.
后来，司马光奉命编写一部通史。
Later, the court ordered him to compile a general history.
这部书卷帙浩繁，需要查阅大量的史料，耗费无数心血。
The work would run to hundreds of volumes and demanded endless research and effort.
司马光担心自己在夜间睡得太沉，耽误了时间，于是想出了一个特别的办法：
Afraid he might oversleep and lose precious hours, he hit on a simple trick:
他找来一段圆滚滚的木头，削成枕头的形状，放在床上。
He took a round log, shaped it like a pillow, and placed it on his bed.
这个“枕头”可不舒服了，只要稍微一动，它就会滚动。
The “pillow” was so unstable that the slightest shift sent it rolling.
每当夜深人静，司马光伏案写作，感到困倦时，便和衣躺下。
When the night grew quiet and his eyes drooped, he would lie down fully dressed.
可刚一翻身，圆木枕头就“咕噜”一声滚到一旁，他也立刻惊醒，揉揉眼睛，继续起身工作。
But the moment he turned, the log rolled off with a thud, jolting him awake; he would rub his eyes and go back to work.
日子久了，木枕被磨得发亮。
Years passed, and the wooden block was polished smooth by his head.
仆人劝他换个软枕，他摇头：“软枕舒服，一睡就到天亮，事就做不完了。”
A servant urged him to use a soft pillow. He shook his head: “Soft pillows are cozy; I’d sleep till dawn and never finish.”
十九年后，全书完成，共二百九十四卷，取名《资治通鉴》。
Nineteen years later the book was done—two hundred ninety-four volumes titled Zizhi Tongjian.
后来，人们把那截圆木叫“警枕”，说它替司马光“赶走瞌睡，留下史书”。
People later called that piece of wood the “wake-up pillow,” saying it drove off sleep and helped leave a great history for the world.