It's not nice to be rude to people.
Jane is waiting in line in a busy grocery store while a slow customer ahead of her pays in small change.
Jane wants to get through the line as soon as possible.
Jane waits patiently for her turn.
Jane complains loudly about how long the other customer is taking to finish.
Customers ahead of her are processed efficiently and soon Jane is on her way.
The other customer gets upset and flustered and has to begin counting out her change again, taking longer to pay.