The sad thing about negative karma is that most of it is utterly unnecessary, a waste of time, energy, and other resources that could be put to more productive uses. Next time, before acting out of spite or reacting impulsively out of anger to hurt another person because they have hurt you, think about the price in karma that you will have to pay one day for your actions. What you do will one day be done to you. If not in this lifetime, in another. In the end, nothing we do is without consequence.
The wise person knows all this and does good things, building positive momentum and good karma to move forward in his life. The foolish person goes on blindly ignoring the Law of Consequences, digging a deeper karmic hole that he will have to climb out of in the future. More often than not, that climb is long and laborious. When we choose to resist the inner imperative to grow, we are choosing to let our karma and our toxicity control our life.