At one of my cousin's wedding reception, the groom asked the priest to give a blessing/toast to start the festivities. He said something that rang true..and I've seen it play over many times:
"A woman marries a man thinking that once they're married, she will change him. A man marries a woman thinking that once they're married, she will change. The secret, of course, is truly accepting the person that you married for who and what they are. The only thing that can be changed is your own view and attitude toward any given situation."