Because white is the color of happiness, and today is the happiest day of her life. A man is said to be incomplete before he's married. After that, he's finished. Marriage is an investment that pays dividends if you pay the interest. Love is an itch around the heart that cannot be scratched.
Marriage is like a barter trade.
There must be a double coincidence of wants. Husbands these days are like fires. They go out if left unattended. Love comes in three rings. The first is the engagement ring.