If you believe your life so mundane or inconsequential that you require an adversary, I feel bad for you. If in your need for a nemesis you are willing to take an innocent person and cast them in the role of villain, you aren't a good person. In fact, I'd go so far as to say you're a remarkably bad person.
Georg Simmel once said, "nothing unites a nation, or any group of people
for that matter, quite like having a common enemy," I don't think
however that he meant for you to make one up. I definitely don't think
he meant for you to make up several just so you can move from one to the
next without pause. That's just unhealthy in a you-need-a-psychologist way. Perhaps even in a you-need-to-be-medicated way.
You may feel more important for a day, perhaps even a week or two, but in the end you are still alone. Your life is still mundane; you still feel inconsequential. And the object of your undeserved malice? Their frustration and bewilderment has faded and they've moved on with their life. Creating enemies for yourself is a band-aid, but you're still bleeding out.
What you need to do is take a step back and review your life and your choices and try to discover the underlying issue. Else, your life will be filled with enemies, but you'll never find fulfillment. Any friendships you do have will continue to be fleeting and about as deep as a puddle.