They had an interesting interview this morning on PBS - don't know the name of the show or the book, but it was a divorce lawyer who had written a book about divorce/marriage. (Yes I know, I am helpful with details.
) One of the ideas brought up on the show, was that if you're starting to get serious about someone, instead of acting out the marriage (moving in with them, etc.) in a sort of trial marriage, you should instead do a trial separation. If you find you can easily live without the person, they're not the one for you. If you find out you cannot imagine your life being happy without the person, then they are the one for you.
Statistically, couples who "act out" the marriage before getting married have a much higher rate of divorce than couples who do not. I find that interesting in light of this interview...