It is different for everyone. Maybe 10-15 years from now you will feel the same or maybe you will feel different. At the age of 20, you have a lot of time and you are in the phase of actually exploring different areas of life. Marriage or long term companionship is probably less of a priority for you at the moment. I'm 28 years old and as of now, I've finished school, obtained a degree, and done a bit of traveling. I know there are more things in life I would like to explore but as my peers are starting to get married and have families, I fear I won't have anyone around to explore and share those experiences with. Sure you may have the same friends but the friendships always change. Over time, you desire that long term companionship just so you are not so alone in the world. But I have agree that the idea of marriage in general doesn't thrill me. I don't need a princess wedding or anything of the such. The promise of commitment is nice but so many people take vows so lightly these days, why spend a fortune on an event that is really only held together by a string.