" The “Mind Like Water” Simile In karate there is an image that’s used to define the position of perfect readiness: “mind like water.” Imagine throwing a pebble into a still pond. How does the water respond? The answer is, totally appropriately to the force and mass of the input; then it returns to calm. It doesn’t overreact or underreact. Your ability to generate power is directly proportional to your ability to relax. Water is what it is, and does what it does. It can overwhelm, but it’s not overwhelmed. It can be still, but it is not impatient. It can be forced to change course, but it is not frustrated. Get it? The "

― David Allen , Getting Things Done: The Art of Stress-Free Productivity