X: I don't think you changed. I don't think anything changed.
Y: Really! You don't think anything changed? Let me enlighten you then. When I met you I wanted to marry you. When I met you I wanted to fall in love, I wanted to be loved back, I wanted to settle down, I wanted to get married. When I met you I had hopes for children, when I met you I thought I would grow old with you.
When I met you I was young. Now I am old. I don't want to get married, neither to you or to anyone else, I neither have hopes for children nor I want them. I don't feel like I want to grow old with you, I have crossed half the way alone and it was fine.
When I first met you I wanted life, and life was you. Now, I have life and there is no place for you.