A Thirsty Belief: what if i die with a smile on my face

What if I stick a smile to my face and live in the shadow of a lie my entire life.Daisy said those words and cursed her very own happening and happy life. She used to be the happiest in times she shared with Mihir and he shared the joy too. Then what made him suddenly leave without a reason? Why did he say that they would never meet again while breaking his own heart? What made him leave Daisy to grieve her for her entire life?  What made Daisy lose all her happiness? Was she ever able to be happy again?Was she able to fullfill her prayers of dying with a smile on her face?