Sometimes human can be impatient. They can be impatient to fulfill what their needs and wants, especially if they do not get it in a faster length of time.
You must have been familiar with the method of queuing. The line is used to regulate people who wants to get something which cannot be provided directly. But the consumer needs to sacrifice their time in the line. In other words, the time for waiting is opportunity cost.
However, there are several people who be patient as the others and they tend to break the line, the purpose it to attain what they need and want immediately.
Sometimes, I broke the line too. One that I remembered was the queuing in the canteen. After buying the mineral water because the line was not clear enough, I went straight to the front and paid my water without paying attention to the line. Because I was in hurry and there is a chance to do so. Also, sometime the line was not clear, it was because there are some students who stood in front of the cashier even though they have done buying the food and drinks. Beside that, the line sometimes is not straight and covered by the students who talk to each other in the canteen.
I know that breaking the line is not good to be done frequently. But, I know the situation. It would not break any line or rules in the public services or public transportation. I would definitely obey it.