The reason so many people don't prepare can be summed up by something my first girlfriend in college said. Don't mean to offend anyone by talking about something personal, but here goes...

Our relationship quickly developed into a sexual one. First time for either of us. Early on, I suggested that she consider some form of birth control, as I was doing my part. She said, "I think that would make it too real..."

Most people IMHO don't want to think about preparing because "that would make it too real." As Doug mentions in "Prepared to Survive", a lot of people think it will always happen to the other guy. Chances are, at least once in our lives, we will be "the other guy".

My girlfriend chose not to use birth control while I continued to. When she got pregnant, she found out how "real" things could get.

Always assume you'll be the other guy...plan for that, and you'll be a lot better off.