You should not waste your time by committing unimportant details to memory. 

Your focus should be on understanding the bigger picture, on how things relate to each other.

A mental model is a mental, simplified depiction of how something works. It influences our perception, decisions, and behavior. 

Learning means upgrading your mental models. The more models you have — the bigger your toolbox — the more likely you are to have the right models to see reality.

• Active reading: is reading with the conscious intention to understand, integrate and evaluate the information you’re reading.
• Passive reading: where you just take the words in.

It's a visual technique for summarizing the material that is specifically designed for the purpose of building a mental picture and seeing new connections. Mind-mapping is great for getting the core concepts of the book and ‘seeing’ how they relate to each other.

It works great for understanding the broad picture and updating your mental representation of your reality.

After you’ve completed a chapter, write bullet points on what you want to take away from it.

It will give you a concise list of bullet points per chapter, without interrupting the flow of reading and without you having to write stuff you don’t care about.

The QEC (question/evidence/method) described by Cal Newport: "Reduce the information presented to you into questions paired with conclusions. Between the two, list the evidence that justifies the connection. In other words, the questions and the conclusions become a wrapper around the raw facts — transforming them into self-contained ideas."

Intentionally direct the workings of your subconscious mind while you’re sleeping.

• Every night, take out an empty piece of paper and jot down thoughts and a follow-up question relating to what you’ve been trying to understand. 
• Every morning the first thing you do after waking -  answer last night’s question.

What you can’t explain to others, you don’t understand yourself.

The single best strategy for organizing constant growth is by involving fellow human beings. To test your understanding of something — anything — explain it to someone.

Acquiring information and learning are not the same thing.

To learn, we need to get the information into our latticework of mental models. For a higher return of investment of reading, we need to engage with the information we read and reflect on it.