I've been married 29 years, the courtship with my husband lasted only 6 months. When I met him, I had a boyfriend; had a couple other bfs previous to that boyfriend. Was 23 when I met H. I said yes to marriage because I felt secure with him, very emotionally close, admired his intellectual capacity and his body, plus the sex was often (sometimes daily or more) and great. I had some, but not all of these things with previous boyfriends. There have been a lot of ups and downs during our marriage but I have always been attracted to him (even when I am angry with him). Marriage is a commitment that effects the trajectory of your entire life--both good and bad. Hopefully there is more good than bad in every marriage--I believe my marriage has had many more good things than bad things. When things are bad, I try to remember all the good times and things we have accomplished together.
The thing that ebbs and flows most in our marriage (is the most challenging for me to maintain) is true emotional closeness. Also, what Scorpiosis says about it being good to talk about "How many kids, how we'd divide up parenting duties with our careers, where we would spend holidays, where we would send kids for school, how much we would spend on a house, etc" is good advice. I was so "happy go lucky" in my youth, none of these things crossed my mind and they all came up during the course of marriage. They mostly didn't cause that many problems except for differences in philosophy in regards to raising our children. It would be a good thing to talk about if you want to have children and how you would want to raise them prior to marrying. I didn't, I just jumped right into it without thinking anything through.