Why do I experience things like this?

I've had this thing so many times. There is a man I like him and that person likes me at first. Then this man suddenly cuts off the conversation and becomes a ghost. then it suddenly appears again, this time I don't care and it bothers me like a pervert. Although I have blocked him from many social media, he is harassing from other accounts from other places. When I give those people a chance in the first place, why don't they take that chance and why do I become valuable to that person when I treat a man like an animal? Why are men acting so weird?
Why do I experience things like this?
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