Every act —ours and everyone else´s— is the product of causes and conditions.
The rancor and resentment that we feel when these acts hurt us, at whom or what are they directed? At someone compelled by a causal series to act in this way? At the impersonal series of causes and effects itself?
What is the result of harboring these feelings? Who suffers? We do. Who benefits? No one.
Can we control the acts of others? We can hardly control our very own! It is a colossal waste of time and energy to worry over that which is not under our control.
Our great Teacher Shantideva stated:
If it can be solved, there is no need to worry.
If it cannot be solved, what is the use of worrying?