Neither she knew nor his friends. He was planning something that would change his life forever. All he wanted was her to be happy, but should forget him and move on.
She decided to end her life, one day.
And then he realized it is better to bring happiness for her now and then leave her someday when she is ready to face the real world. May be he is wrong. But for him choices were least between her and his dream.
He chose dream.