Understanding Flowers, Year After Year

Most people will meet three people like these in their lives:

The first is made for you, one of a kind in all the world.

The second catches your eye for a moment, then stays in your thoughts forever.

The third is someone you would share life and death with, wishing to be together always.

But who is the one who makes the mountains of Wu seem insignificant, the seas seem small, and becomes your destined beloved?