We live in a world of perfectionism. In our daily dealings we expect things to go a certain way, and when our expectations aren't met, we are shocked. We angrily complain. Why was my coffee bitter? Why was the bus driver rude? Why was my doctor running so late? We judge people. The barista must be inept. The bus driver is an asshole. My doctor cares more about long lunches than seeing his patients.
But what are we forgetting? These people are also struggling through life. Their problems may be more significant than we think. Perhaps the barista's mother had just been taken to hospital. Perhaps the bus driver had recently been given notice of redundancy. Perhaps the doctor's car had broken down. Your moment of inconvenience may be relatively small on the scale of challenges people have to overcome in their lives.
So, when judging people for their mistakes we should remember that they may be having a difficult day. Life is hard on us all. But we can help each other with patience and understanding.