Some people are very self-conscious. As a doctor, he recognizes the amount of change is minuscule, the effort expended to point it out is barely worth it, the clerk may have done unintentionally, because schools suck and this is the best the market could get at the wage they are willing to offer.. all sorts of reasons not make a big deal.

But.. deep down, internal scales are off. Because it is not about the money. It is about balance. it is about principles. It is about getting what I am god damn paying for, which includes courtesy of getting the right change.

It is insignificant in the long run, but it isn't completely without merit.