Why.. is human desire so unsatisfying?

Cinderella's glass shoe was the perfect size.... so why did it slip off as she ran? It must have been to attract the attention of Prince Charming. I don't see any other explanation.

Right now I am working to polish the shards of my dreams.

That overflowing feeling became love. But I don't sing for Ren's sake. I sing for myself everyday.

If I ever fall in love again, I would like it if it were a slightly cold guy. Someone who won't constantly mind about my childish needs but who, the day after the quarrel, for example would offer me a flower accompanied by a sweet note That's kind of guy I need.

We didn't say good bye. But we knew it would be the end if we were apart. There was no reason to call or write letters. As it would have been meaningless, if we couldn't hold each other tight.

Why.. is human desire so unsatisfying?