First consider your best friend of the opposite sex. They are generally a person who would stick with you, no matter how bad things get. This is the person that you would call if you were in trouble, or needed someone to talk at 3am because you just can't take it another second. You know you love that person. If your potential spouse isn't that person, your marriage can't last long. In a single person's life, best friends can come and go. It could be anyone you are willing to put your trust in at a given time. There isn't anything transient about that relationship in a marriage. But with all good things, there tends to be a trade off.
One trade off, free time is a valuable commodity whether you are single or married. Before making a commitment as big as marriage, you must decide if you are willing to share it unconditionally. If you aren't willing to share it, then maybe the single life is ideal for you, because marriage means that your time doesn't belong just to you anymore. You now have someone that has claim on it, too. Gone are the days of just packing up and disappearing for the weekend; because you now have someone else that has a say in that area. When you're single, if you feel like going fishing, you don't have to consult anyone on his or her agenda. You can stay gone all weekend if you want to, and there isn't anyone you've left at home to answer to, or to worry about you when you're gone too long. If you feel the right to pick up and leave whenever you want to is the most valuable thing that you have, then you should give it some serious