Love has two types: the common love (no sexual interest involved: you may love your family, friends, dog etc)
                                 the passionate love (with sexual interest involved: lover, spouse - at the beginning)
The first one has few social reflections, none the less, the latter is very well socially confined. Yeah, yeah, you can play, but at a certain point, everybody just gets crazy being afraid of social loneliness (I must add not without reason) and hurries to “get his or herself well confined” in a peculiar sentimental conglomerate, called “marriage”. 
 So, there were two persons freely loving each other, but society doesn't support free stuff altogether and decides that you have to institutionalize your feelings, institutionalize your sex, institutionalize your material situation because that is just the way it has to be. If you don't do it, you will without any doubt experience SS: social solitude. Why? Because which wife would like a good looking girlfriend coming all the time to their house... she may steal her husband... So, better not even invite. With men, it is slightly different. Men, in many ways, think more freely than a woman, and yes, man do interact with unmarried friends. Woman are different. They have the “married woman's club with children” thing, and anybody, who is unmarried and without children it's like a strange exotic parrot from another continent. You may look at it, ok, but definitely don't want to have anything in common with it. Of course, it is not just their fault. Unmarried people, without children, sometimes are painfully bored in the middle of “family guys”. And yes, I do prefer rather being alone, than listening to what  a 5-month-old baby did after being fed. Is that a bad theme to talk about? Absolutely not. I talk a lot about nutrition, that doesn't interest that many people either, so in no case I can criticize anybody of their interest. I am only trying to highlight the difference between people, who from whatever reason choose one way or another as general social behavior and interest. 

 Of course, the institutionalization of love has its basis: somebody wouldn't pay child support, wouldn't give money for the well being of the family...etc. Even the bank has a program for married people. More advantageous credit for example. They never have advantageous credits for ambitious singles. Never. But they have for families. So, are singles socially punished? Yes, they are. You choose the road of being stronger and free, so you just have to pay the price for it. Of course, some may say, that singles don't have children, why to support them? Well, if there would exist for example advantageous credits, or help from the state for single mothers, for example, we, single women would think about having children, and let's say “contribute to the future taxpayer generation”. But there doesn't exist such stuff.  Nobody wants you to be free. Nobody. Free people think. Think more. Nobody likes thinking people. 
 Why is marriage not a good idea? Because love has this damn annoying characteristic of not lasting forever. Why it doesn' t last forever? 
 First of all, it can't last if you are different “opposites attract” scenario:  but do opposites attract? Sure! Is it a good thing if opposites attract? Can a relationship function if you are 100% different? When is there a point when the fatal attraction just turns into hate and disgust? When the sexual passion disappears what does remain, if you are so different? You have to realize, that the little things, that “turn you on” in the beginning of a relationship are the exact ones, that will annoy you later on. What you find exciting, intriguing and eventually raises your interest because it is different than you after the sexual boredom installs itself in your relationship, those exact things, behavior patterns will slowly but steadily start to raise, this time not your interest level, but your “temper”. 
 The second scenario, when you are similar: you have similar interests and you are just overwhelmed by the “huge quantity” of similar thoughts and interests you get to observe at your partner. Oh, my God! You are floating of happiness. Till a while. Why isn't that just enough forever? Cause you just get bored of not arguing ever, hearing nothing new or what would raise your interest. Stupid, but true. And of course, the sexual boredom installs itself too. 
Both cases end up in the same place. One is with more stress and arguing, the other one is more boring but result in the same. You don't want the guy, because he annoys you or hurt you at arguing, or you don't want the guy, cause you simply are too bored of him. 

 One thing is sure: nothing lasts. That is sadly valid for love too. Remaining in a relationship for a long term is a social and many times only a material compulsion. 

 Love is a strange combination of physical and psychical attraction. Actually, that is exactly the problem with it. I was contemplating on the love situation, always thinking in favor of one or the other: what was the problem, the psychical boredom or the physical one? Or which one in the higher percentage than the other?  The answer is, both of them are equally important. And ignoring one or the other conducts even faster to the deterioration of the relationship. 

 Don't worry. There is no solution obtaining the big Love till death separates us. But staying in a relationship may occur when you are just willing to give some slices from yourself, called “compromise” - boring I know. This is just a thing with which you can not do anything. Look at animals, they don't stay with their partners till deaths tear them apart. They just don't. We evolved too. The first “interaction” between a male and female homo sapience didn't take place in a Gothic cathedral either. 

 How the heck could we institutionalize love? What is next, to institutionalize other feelings too? 

 This social compulsion of tying two persons together is no physical “can't do without”. You can not do without eating, drinking. But being in a funny outdated Renaissance style white dress  one day in your life is not a necessity, it is a social indoctrination.  

 Nevertheless, if you ever plan on getting married, do it before 30. Maybe it won't last, but one thing is sure. After 30 it won't last either. Waiting won't give you the right person. It will only give you more persons. It's like wanting to buy the shoe with extra high heels, but damn comfortable. The two just don't match. 
Don't think so much about it. Just do it. Or don't do it, only don't expect that you will find any kind of big love after this age, and the big love before is with expiration date too.