Sit down and watch a mechanic work on your car for three and a half hours. Just sit there, grab a snack and watch them work. You will never be careless with your car again. It takes a lot of hard, talented work with crazy tools and elaborate steps you didn’t even know existed to get it fixed. It takes experience, care, attention to detail, coordination and focus. Until you stop and really perceive the depth of your ignorance of other people’s trades, you will never truly know the value of their work, or of your own.