If more students have forgiveness education when they are young, then this will give them a chance to more deeply see the inherent (built-in) worth of others. As we see that all people are special, unique, and irreplaceable, I truly think that deliberately hurtful verbal attacks on others will lessen.
If this is a pattern and if he sees that others are hurt (which you imply that he does), then, yes, I suspect the same: hidden (from him) and deep anger. He may need to courageously explore who has hurt him in the past and try to practice forgiving, if he chooses. It might lessen or even eliminate his hurtful sarcasm.
Forgiving others is not done exclusively because it has excellent psychological benefits, shown by research. Forgiving others also is good in and of itself because it is a moral virtue (as are justice and kindness and respect). Showing goodness as the goal of forgiving (rather than deriving a psychological benefit) is sufficient for forgiveness to be a part of your and others’ life. To address your point directly, as we both know, reacting to injustices only with temperate, short-term (not unhealthy) anger is not likely as part of the human condition. Thus, the need for forgiveness, for psychological reasons, will continue to be alive and well on this earth.
Humans are **aware** of themselves. They are aware of others as well. This awareness leads to the question, “What is right and what is wrong?” When what is right fails, humans are aware of this. A central response of mending the effects of this wrong-doing is forgiveness (the awareness that even though the other did wrong, one can accept the wrong-doer as a person). So, awareness starts the sequence which leads to forgiveness. No other species seems to be self-aware like this.
A key to entering into what we call the Decision Phase of forgiveness is to commit to doing no harm to the person who hurt you. In other words, try to commit to not insulting this person or not speaking badly about this person to others. Note that I am not suggesting a **positive** response such as cultivating, for now, empathy or compassion or even love. Instead, I am advocating your refraining from the negative. This commitment may help you to decide: Yes, I now want to move more deeply into a decision to forgive this person.
In such cultures, as you say, it is best to give the gift in ways that respect the norms of the culture. One need not give a gift within a box all wrapped up in gift-wrap and a bow. One can be more subtle about it: a smile, paying respectful attention to the other, not speaking badly to other people about the one who hurt you. A gift is a generous and often unexpected kindness which can be done tastefully by knowing the norms of a given culture.
There are at least two different meanings to the term “to forget.” The first one, which I see as unhealthy, is to suppress the knowledge that the other is a danger to you. It is important to remember that some people are not “on our side.” The second meaning of the term “to forgive” is to move on, as you say. So, you can move on from a situation while you see the humanity in the other (as you choose to forgive). As you see the humanity in the other, it is important to acknowledge the other’s weaknesses if he or she still has a pattern of behavior that is hurtful to you.