力量不是来自你能做什么，而是来自克服你曾经认为自己无法做到的事情。

魔鬼最厉害的伎俩就是让世界相信他不存在。

The chief beauty about time is that you cannot waste it in advance. The next year, the next day, the next hour are lying ready for you, as perfect, as unspoiled, as if you had never wasted or misapplied a single moment in all your life. You can turn over a new leaf every hour if you choose.

if you are walking in the hell, keep walking!

系统设计的未来在于将形式化方法与传统工程实践相结合。