成本效益分析(Cost-Benefit Analysis)

　　during the six-hour flight to new york, i did a cost-benefit analysis. i asked myself: “what was the cost of just listening when lyda called out the warning? zero.” i then reasoned: “what was the potential benefit? what could have been saved?” several potential benefits came to mind, including her life, my life, the lives of our children, and the lives of other people.
　　when someone gives us something that has a huge potential benefit—and costs us absolutely nothing—what should we say to such a fine person? “thank you!”i landed in new york feeling lonely, guilty, and ashamed of myself. i immediately called lyda and told her my cost-benefit story. i assured her: “the next time you help me with my driving, i am just going to say, ‘thank you.’”“sure you will,” she said with a laugh (sarcasm free of charge). for some reason, she seemed to doubt that i had undergone a true religious conversion.“just you wait. i am going to do better.” i continued.“we’ll see.” she replied.