When the supervisor refused, instead offering the service the store has where the customers scan the items as they pick them up in the aisles in the hope of speeding up the check out process, the mother took it upon herself to continue to give a nasty look at the supervisor as she had to go through the normal process of paying for her groceries.
After I checked out, I went to leave in a long line of people with carts full of groceries, all moving as fast as they could in an orderly fashion as we all tried to get to our cars and back to our regular lives. A young man with a soda decided to just continue to cut in front of people since he was not pushing a cart. He saved himself a whopping three seconds by doing so.
While I was driving home, a motorcycle sped by me at a speed that could only appear to be at least 20-30mph over the speed limit on a four lane highway. When he came up to two cars that were practically next to each other heading in the same direction, the motorcyclist decided to take his own life into his own hands and weave in and out of the cars along the dashed line that separates the lanes in order to maintain his speed and leave the slower cars in the dust.
When we think about sportsmanship, we commonly think of athletic competition as the common arena to exhibit it. However, the same rubric of good sportsmanship can be used in so many other places in life. As we are all trying to achieve a goal in the above examples (checking out, leaving the store, and driving home), sportsmanship can be exhibited through the observation of cooperation. We are all trying to achieve a common objective, much like athletes have the objective to win. However, we are not competing with or against anyone. The goal to check out, etc., is the same for everyone, and one person's victory does not equal another person's defeat; everyone can be philosophically victorious. Cooperation (and, thus, the necessary patience) can go a long way to help everyone achieve the same goal.
In short, there's no reason to look for an advantage to check out quicker, cut in line to get to your car, or speed past other cars to get home unless there is a true emergency. In searching for these advantages, we actually put more people at a disadvantage because of the waste of time, the lack of guarantee that the maneuvers will pay off, and the upset nature that more people will exhibit.