Relationships- What's the big deal?

For the longest time I have been against serious romantic relationships at my age- 21. I have been against young marriages because I just think they tie you down and don't allow for individuals to explore the world. I don't understand why everyone is in a rush to find this significant other, get married, and "settle down." However, I have realized in the past few weeks that relationships don't necessarily mean death, it is only because of my friends and their perceptions of what a relationship should be that I have been completely negative about it.
Last year my room mate constantly had a boyfriend, two long term relationships. Ever since I have known her, as a matter of fact, she has had a boyfriend. She's the type where they get a boyfriend and they forget they have friends or lives away from their boyfriends. I guess it didn't help that she was addicted to marijuana and "getting messed up" and that's what her younger, less intelligent and unmotivated boyfriend was into as well. Which on a side note, I saw in the health clinic the other day that there is actually a syndrome for that called "amotivational" caused by weed...really? Either way, she exhibited everything I hated about young women getting in relationships. Pretty much all of my friends who had gotten into relationships had forgotten that they had a committment to keeping their friendships.
One day I realized that relationships didn't have to be that way. I was thinking about why it was so normal for some couples to spend all of their time together and not normal to me. It took me a few years to realize that I should look at my number one role model of a relationship- my parents. I realized that my mom had always had her own thing going on and in a sense made a life separate from my father (because he was away all the time) and made girl friends that she frequently did things with. She always hosted parties and went out with her friends, which I admired and always thought was a normal thing. When I came to college and suddenly saw all of my friends lives dissappear when they began relationships I looked down on them. I was saddened to think that people could be so fast to just give in to a boy and leave their friends behind.
The other day I was having a conversation with a girl who is 3 years younger than me and is married and another girl the same age who is in a relationship. The girl in the relationship asked me, "can you imagine being married right now?" I thought about it for a minute and realized how many of my friends were getting engaged, married, or in serious relationships. Afterall, I am a rising senior in college- a lot of people find their husbands and wives right about now. I simply answered her that I don't think I could be married but then again I have never dated anyone, looking back on it now, that I would have wanted to spend the rest of my life with. Obviously that is why I am still single. But I also defended the girl that was married - which I couldn't believe that I did because I have always been against young marriage.
I realized, "to each his/her own." What is right for me isn't right for her and vice versa. I realized I don't want to settle down right now because I still feel like I haven't experienced enough to limit myself to a relationship and that's how I view life. Some people are content getting married and staying in one town their entire life, some people want to find another person to share their experiences with... I just want to live. I want to go out with my friends, have a good time, and not worry about who is wondering what about me and have to answer to some one. I also don't want to feel like I have to spend time with someone if I don't want to. I'm not going to pretend like I don't get lonely or that sometimes I feel like I should be dating someone by now.
It's funny my friend who all of us thought would be married by now is now changing her tune. She jokes that she will never get married and so forth. She hasn't found anyone yet... which is okay but not traditional in her family. I think we all worry about not finding someone but why is it that we have this pressure to be with someone by the time we finish college. It's the society that pressures us, especially women to make a decision by the time we graduate college. I believe I will defy the odds and go ahead to graduate school ... then get a career ... and then maybe just maybe I'll find the right man to share my life with.