The difference of dating and being married?

I was out with my best friend for dinner then we got into this topic. Well, we are close, so I was shocked that she disagreed with everything I thought about dating and the post marriage life. So I penciled down my half-baked belief that the I stand by that dating is the same as being married. Two point, 1. The responsibility before and after getting the marriage certificate, in an utopia kind society, while people would be acting no difference in times, its indifference as the bonding is far forged prior to the marriage due to higher moral and social responsibility standard embedded in all people of the society; for not in an utopia place, which is us now, everyone is somewhat in the nature of self-serving, the responsibility part of it (the marriage) would be enhanced by the certificate of marriage in some ways. I'd think if I'm getting married, utopia or not, I'd see what I'm dating would have no difference in what I'm marrying to. That's why the whole point of dating, living together, and traveling together. This goes far beyond just responsibility, that also includes moral standards (monogamy), concept on raising kids, lifestyles, all small things from chores to ideas. 2. The vision of marriage, a taboo topic of myself which has an in depth view of involving bickering, fighting and emotional inflating pain to another, something I'm always running away, so if I'd say an ideal marriage, those would be not be part of my vision and I'd do all things in my power to not have that or to have it not in that way. Thus, to me, there is no difference. The certificate is piece of paper, no doubt, to some, it's sacred; to some it's just a piece of paper. But that's just my view.What do you think?