It reveals a great deal about how memory works. Zeigarnik suggested that failing to complete a task creates underlying cognitive tension. This results in greater mental effort and rehearsal in order to keep the task at the forefront of awareness. Once completed, the mind is then able to let go of these efforts.

You can even use this psychological phenomenon to your advantage.

• Break up your study sessions rather than try to cram it all in the night before the test. By studying information in increments, you will be more likely to remember it until test day.
• If you are struggling to memorize something important, momentary interruptions might actually work to your advantage. While you are focusing on other things, you will find yourself mentally returning to the information you were studying.

Pursuing productivity for its own sake is counter-productive. 

Most people feel able to complete more tasks when they start using time-management tools, but they don’t bear in mind that they can’t keep increasing their productivity forever, and they commit to more and more. In a few weeks, they are more productive but still frustrated. 

Back when more people worked in factories, laborers did not have to deal with time management. At the assembly line, time was managed for you.

Freedom comes with responsibility: you have to think a lot more about how you manage your time.

Rather than trying to work flat-out, break down your day into a series of work-sprints with a short rest period after each session.

Set a timer for 25 min and focus exclusively on your work for that time, take a 5 min break, and repeat.

Some people find that taking a 5 min break destroys their flow. But it does help to break long complex tasks into a series on manageable sprints.

The 2-minute rule is a strategy for quickly assessing and taking action on small tasks so they don’t take up too much mental energy.

Ask yourself if a task is going to take you 2 minutes or less. If so, just do it.