I thought the comment below from the Jeff Bezos interview was important, especially given some of Charlie Munger's comments on multi-tasking over the last few years, so I wanted to highlight it separately in this post:
On phone addiction and multi-tasking: Mark says his brother Jeff is surprisingly present, and rarely distracted by his phone. Jeff explains that “When I have dinner with friends or family, I like to be doing whatever I’m doing. I don’t like to multi-task. If I’m reading my email I want to be reading my email” with his full attention and energy. Jeff exhibited this resistance to multi-tasking early in life. At Montessori school, he’d refuse to move on to the next task as the day progressed, so the teacher would literally pick up him and his chair and move him to the next project. Instead of constantly switching back and forth, Jeff says he sequentially focuses. “I multi-task serially.”