We common people tend to love the other party more after a breakup.

The interaction and mutual influence between people can lead to the formation of certain mentalities. When someone continuously shows admiration, the person being pursued will develop a "self-centered" psychological state, feeling extremely accomplished, universally adored, and overwhelmingly confident. This psychological state can be intoxicating, bringing immense happiness, and over time it becomes very stable and hard to break. When a lover suddenly leaves, the environment that sustains this confidence is disrupted, leading one to feel instantly worthless. To regain the previous environment that supported their confidence, a person might try every possible method, even resorting to self-harm or harming others.