Answer:
Its easy to ignore or forget issues if you don't render or recognize its sustainability
Step-by-step explanation:
In any case people have faced issues in our world and people react to them in different ways. One of which you described is ignorance which is most common upon younger generations. When we look at ignorance in general its dictionary definition is lack of knowledge. But I feel the adopted term is more of lack of knowledge or care for a situation or a lack of stimuli to a feeling or emotion. In any case its very common to face ignorance now days and have negative emotions still. If anyone has ignorance in a certain reaction to a stimulated feeling people would most likely ignore it. This effect however does allow our mind to deteriorate that feeling further and further until we no longer feel that emotion or have a care about the case. Most people say its just "acting tough", which is in some areas but it might also be because of some sort of other feeling you had but cant remember or have (like the def of ignorant) lack of knowledge.