They help you know what to expect in the future. And know what decisions to make when a problem or situation that comes up in a relationship. And they will allow you to trust certain people and not to trust people and, so you can pick your friends wisely so you wont have any problems in you future. And if you do you will know how to handle it by having a problem in your past so you wont have to have a big ordeal over it. An example in my life would be when my friend Chris had a fight about a girl and who would go out with her and when it was me he was mad at how we let a girl ruine a friendship that lasted over eight years.