Sexual desire and a need for intimacy

Obviously some people choose not to have sex at all, others do it frequently with one partner and others have a lot of partners...I know there's not really a "normal" amount of sex...
However, I'm a college student and it seems like most of my peers fall on one side of the spectrum or the other: some choose not to, some want to but haven't; on the other side, there's all the people who party hard and get laid often. I have had three long-term relationships, boyfriends in the double digits and sex with oh, about ten partners. Yet, I've gone through long periods in my life where I am celibate; this past period lasted one and a half years with absolutely no intimacy. At times it was exactly what I wanted and at others I felt lonely and unwanted. I was traveling a lot so it would have been difficult to connect with anyone for more than a month or two. I had made the decision to take some time off from sex, but at the same time, no one approached me about it. I don't know if I was unconsciously closing myself off or if I've lost some of my sex appeal, or if the timing was just poor. It seems like my friends and peers are constantly hooking up or falling in love. At times in my life it's been easy to meet someone, but there's been long periods where my love life has been a dead end. Sometimes I think I'm doing something wrong. Do you think it's normal I'm not frequently the object of spontaneous or long-term sexual encounters?