Procrastination is easy because there is an immediate reward (feeling better) as soon as we abandon a distasteful task. On the other hand, it's possible to reward good habits; finding ways to reward good study habits is important for handling procrastination.

Procrastination happens because seemingly unpleasant tasks actually trigger a brief and mild brain response that is similar to physical pain. To avoid that discomfort, we will very likely shift our attention to something more pleasant, which will provide only temporary satifaction. The good news is that the discomfort is related to anticipation only, and typically subsides very quickly once we actually get started on the task.

A chunk is made of pieces of information - thoughts, ideas and techniques - that are related by their meaning or use. In neuroscience, it's a network of neurons that often fire together in support of an action that you want to perform smoothly or efficiently, like hitting a baseball or playing a piece of music. For math and physics a chunk could be a method for solving a particular type of problem like a linear system of equations. Deliberate practice and repetition builds strong memory pathways, and helps create chunks. With time, small chunks come together to form larger chunks. It's like learning a song on guitar: we learn brief passages, focus on and practice the more difficult parts (small chunks), then eventually put all the bits together in a coherent piece (larger chunk). Once the chunk is formed, the action - playing a song or doing a particular type of math problem - becomes second nature.

Here's a common myth based on old science: the number brain cells you have at birth are all you'll ever have. In fact, our brains produce new neurons every day in the hippocampus and we can make good use of them with strong learning habits.