On an ordinary day, an ex-partner, long out of contact, posts a new update. In the image, he dons the familiar radiant smile you used to see frequently, yet he's embracing someone unknown to you, celebrating an anniversary on a date you are certain occurred during a cold war before the official breakup. Realizing his infidelity fills you with anger and sorrow. As time passes, he doesn't seem to face any so-called karma; instead, his life appears to flourish, igniting a long-simmering fuse within you. Your thoughts are overwhelmed with questions like, "Why am I the one hurt, and why is he doing better?" You might start to think you were an obstacle in his succeeding relationships, denying all aspects of your relationship and wondering if you did anything wrong to cause the breakup.

Why are we so affected by this? According to Social Comparison Theory by psychologist Festinger, we have an inherent tendency to compare ourselves with others to evaluate our competencies, worth, and circumstances. Witnessing a cheating ex flourishing creates a downward social comparison, leading to extremely negative results. The idea of "evil begets evil" is deep-seated in our subconscious, causing anguish when perceiving our situations as worse than those of people who supposedly deserve worse. Such disparities profoundly impact our self-worth, prompting doubts on whether we weren't good enough, leading to betrayal, or feeling undeserving of better, striking hard at our self-esteem and inducing feelings of loss and injustice.

When you start to doubt yourself, the flaws in the past relationship—unfinished words, broken hearts and promises, missing love—all bring forth reactions like "Am I not worthy of proper treatment?" Yet, it's not that you aren't worthy; it’s that the partner didn’t provide appropriate value in the relationship from the beginning. Confronted with shocking events, the emotions surrounding the breakup internalize as self-disparagement, mistakenly believing personal faults ensure control, shielding against others’ unwarranted malice, and thinking, "If only I were 'better,' events like this wouldn’t occur."

Nonetheless, what truly wounds us isn't the ex themselves. Their success or failure bears no actual relevance to us. The real hurt derives from realizing how sincerely we committed, only to remain unappreciated, leading to questions of "How could I have been so naive?" or "Why didn't I leave sooner?" These emerge disguised as consolation but sting like salt on wounds in conversations with friends or in personal thoughts. This root of self-questioning and insecurity marks the true origin of discomfort and anger—it represents a reaction to past self-pain unhealed and unrecognized.

While these comparisons are unavoidable, we can transform them into motivation for self-progression.

Here are steps to consider after some reflection: 

1. Acceptance and Release: Acknowledge your emotions; resentment, disappointment, and anger are valid but shouldn't dominate your existence. Rather than dwelling on "Why him?", ask, "What do I truly desire?" and "How can I improve myself?"

2. Focus on Self-Improvement: Redirect focus from your ex's life towards yourself. What changes will enhance your fulfillment and happiness? Acquire new skills, form new friendships, pick new hobbies—engage in productive activities to fill inner voids instead of expending energies on futile comparisons.

3. Redefine Success: Everyone presents only their successful fronts on social media, concealing struggles in reality. We can't fully comprehend our ex’s genuine life situation. Redefine your success—not based on career feats or social media approval, but inner peace, self-assurance, and bravery in confronting life challenges.

Remember, happiness doesn't depend on someone else’s misery. You deserve a radiating life, free of comparative binds. Ultimately, this resentment becomes the catalyst propelling self-healing and development, revealing you don't need to fret over anyone else's social media presence, as you've discovered your genuine joy.