There are parts in me who find comfort in reading the section about "The dark side of always-on productivity." but I like this framing: "By letting us re-experience past events, simulate how others feel, explore our values, and engage in learning, maybe the Default Mode Network goes to those places because it needs to." -- in the past, I was optimizing for a false sense of productivity, investing every minute I had in learning and doing. Most of the time, it led to me burning out. Nowadays, I'm trying to optimize for sustainability, looking to grow while being happy as I set my expectations (with my self, my wife, and my teammates at work) early.