First of all, we have already divided people into three categories - friends, enemies and strangers. With friends, to whom we have strong attachments, we do feel empathy and a strong wish to protect, especially if they are our children and loved ones. We are indifferent when they are strangers who are suffering, beyond expressing perhaps sadness at massive road or air accidents that take a heavy toll of lives. When it's our enemies, we sometimes even wish them dead, and rejoice when they die.
The words "utterly normal' implies having no feelings of compassion or care. However, if we can cultivate(and we should) the realization that all beings have been our mothers, and do not want suffering as much as we don't, then we can easily evoke these feelings to move us to act altruistically, be they friends, enemies or strangers, who are suffering.