Law of diminishing marginal DIS-utility

Law of diminishing marginal utility : " A law of economics stating that as a person increases consumption of a product - while keeping consumption of other products constant - there is a decline in the marginal utility that person derives from consuming each additional unit of that product "( http://www.investopedia.com/terms/l/lawofdiminishingutility.asp)

The same law can apply to dis-utility. The definition of utility is important but we will come to that in a moment. Say you have to take a bitter medicine syrup. The first spoon is always the worst. You almost throw up. The next dose is also bad, but you have adapted slightly and is not as bad as the first. The third day, you are getting used to it and don't feel like throwing up. If we define "taste" as utility, then the first spoon provides maximum dis-utility. On the other hand, if we define "medicinal action" as utility, then the first spoon provides maximum utility i.e the body is most receptive to the medicine. The dis-utility of taste keeps decreasing leading to a point where you may not enjoy the medicine but are not at least repulsed by it. Similarly, regular doses of the medicine start making the body immune whereby additional doses do not have the required effect.

My point is, just as anything enjoyable loses its utility over a period of time, anything despicable also loses its dis-utility over a period of time. Maybe that is what is adaptation. Or that is what they call "Getting used to it"