I was talking with a friend of mine just a bit ago and we came up with a pretty solid metaphor for relationships. Building a solid relationship is like building a house...
1. You can't skip steps! If you go too quickly in a relationship, you aren't building it on a solid foundation. Just as it is rather challenging to begin with walls and a ceiling without a foundation, it is difficult to build a relationship without first being good/best friends. Although it is highly possible for it to last a period of time, it is impossible for it to work out in the end. The only way that it could work out is if you went back and redid those skipped steps. Specifically, this is in regard to dating --> bf/gf too soon before a solid trusting friendship is developed. From personal experience (as well as my friend's experience) dating you BEST FRIEND is the best type of relationship you can develop. However, it is rather challenging to go back and develop a friendship after the relationship has progressed and become too physical.