书如其名，暗时间。如果可以用好暗时间，那么实际所拥有的时间会多得多。
大概几个想法：
时间管理
- GTD
- 番茄时间
- TimeBox
- 柳比雪夫--时间记录法
whats the relationship between them.
抓住不变量
区分本质的和非本质的知识。比如说硬件体系结构是本质的，主流编程范式是本质的，操作系统的核心思想是本质的。
Some study habits
reading note
HT take note.
take down some good examples.
thinking all the time
Especially, thinking while going to sleep. it helps a lot.
Three questions when learning a new knowledge.
- What's the essential?
- What's the first principal?
- What's the knowledge structure.
asking question while reading.
WWW + HT + Example.
Question
HT retrieve old knowledge
How to make it meaningful in memory.
