And many don't realize it. I think people can also have qualms or doubts but already be sunk in due to the cost of a 'big wedding' (vendors want prepayment; venues cost to reserve), and all the preparations keep them busy, they get swept along in the preparations and stop thinking critically. It's a very serious thing and being tied to one person in legal ways - better know that person inside and out. I know these sound like cliches but a lot of people get caught up in it. Then there's the public embarrassment and "L" award some will give if it's called off. But it's better to call it off, even at the altar, than to marry someone not suited to the other person, or to marriage itself. I'm rambling a bit because the topic makes me sad.