Which could result from a person who does not finish the prescribed amount of antibiotics for an infection?

For you personally, if you don't finish the course of antibiotics, the infection may appear to have cleared but in fact may still remain and come back stronger and worse. Depending on the infection, that could mean another course of antibiotics is needed or more drastic treatment. Of course, you may just be lucky and the infection has already been cleared but it will do you no harm to finish the course and it is more likely that you won't have cleared it up. Some infections even take more than one course of antibiotics.