It's impossible to forget it completely, but the only way for you to "unlove" someone is by detaching yourself from every emotion and memory that ties you to the person you loved. Some might say about thinking negative things, but that would only lead to bitterness. Rather than doing that, you ought to learn how to set boundaries and reason why it is necessary for you to "unlove" him or her.
In my experience, I've been a martyr in a past relationship that I had. Because of love, I did what I could to make her smile, appease to her every whim, and gave all my strength to give her the happiness she was looking for. to sum it up, I gave it all and it wasn't enough. She keeps comparing me to the other "men" she met, turning a blind eye on how I did my best. She humiliated me in public, slapped me, insulted me in front of many strangers... especially that one time in Ayala...
But after a year or so... I've really had it and told myself that enough is enough. Before we broke up, I did my best to detach myself from the memories I had with her, I told myself that if I keep this up, and use my heart before my head, I will definitely get hurt in the end, and I would not live a happy life. Once the time came, we split, the separation hurt, but not enough reason for me to cry. I gave myself a reason that If I had stayed more in the relationship, mamatay najud ko.
I'm happy now, living a simple and free life... Love is bliss, but once it becomes one-sided, it starts hurting...
But that's the general idea.
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hahaha drama