• Deep work means those professional tasks that push your cognitive capabilities to their limit done in concentration mode (no distractions)
• Shallow work relates to the tasks that do not require much cognitive work (logistical-style tasks) performed while distracted most of the time. They don't bring much new value in the world and are easy to duplicate.

High-Quality Work Produced = (Time Spent) x (Intensity of Focus)

Without explicit feedback on the impact of various behaviors to the bottom line, we will tend toward actions that are easiest in the moment.

Knowledge workers usually lack explicit indicators of what it means to be productive and valuable at work, so they turn back toward an industrial indicator of productivity: doing multiple tasks in a visible manner.

• Monastic: isolate yourself for long periods of time without distractions; no shallow work allowed
• Bimodal: reserve a few consecutive days when you will be working like a monastic (you need at least one day a week)
• Rhythmic: take 3-4 hours every day to perform deep work on your project
• Journalistic: alternate your day between deep and shallow work as it fits your blocks of time (not recommended to try out first).

In order to have a deep work routine, you have to decide the following:

• Where you’ll work and for how long.
• How you’ll work once you start to work.
• How you’ll support your work.

• Downtime aids insights
• It helps recharge the energy needed to work deeply
• The work that evening downtime replaces is usually not that important

It's important to have a shutdown ritual, to ensure that every incomplete activity has been reviewed and that for each you have confirmed that either you have a plan you will follow for its completion, or it’s wirrten down and saved in a place where it will be revisited.

• Sending too much time on Social Media breaks up our time and reduces our ability to concentrate.
• Social Media take away time you could be spending on higher-impact activities. It’s a zero-sum game.
• If you want to eliminate the addictive pull of entertainment sites on your time and attention, give your brain a quality alternative.

Identify the key elements that determine success and happiness in your professional and personal life.

Adopt a tool only if its positive impacts on these factors substantially outweigh its negative impacts.