When you force an undesirable or harmful event on someone, you inflict it on them. You might prefer that someone inflict some physical pain on you rather than inflict you with the boredom of another trip to the annual flower show.
The verb inflict comes from the Latin word inflictus, meaning “to strike or dash against.” If you cause anything bad to happen to a person, animal, or even an object, you inflict that badness on them. For example, someone can inflict injuries or suffering on other people or inflict damage on property. We can inflict pollution or over-development on our environment. It's always a negative thing — you wouldn't say you inflict happiness or love on others.