Once in a person's lifetime, everyone finds this one perfect person whom they fall hopelessly in love with and live happily ever after. That is a mere fallacy, in the real world, this simply does not happen. Yes, people do have common interests and therefore develop romantic involvement, but it is basic common sense that these relationships have a life span and simply cannot last. Real life relationships are definitely more like "The Real World" rather than "Romeo and Juliet". Romanticism is wonderful in itself, and thus two people can live in heavenly bliss, but it all must come to an end somehow. It is a fact of life that couples do break up, and there are many reasons why. There are countless reasons, ranging from cheating to lack of sex to abuse, attributing to breakups.
One reason why couples might break up is money or a lack thereof. If one partner in a relationship is always paying or keeping up all the bills, his/her partner just might grow tired of it and decide that it is a valid reason to separate. For example, a woman who is always lending her boyfriend money for his rent, car note, and social expenses will probably eventually grow tired of it and leave him.
More reasons why couples separate, addictions often result in ugly breakups. Whether it is an addiction to drugs, sex, gambling, or whatever, hardly anyone would be willing to take that on an everyday basis. Most people would agree that it is not pretty to see someone throw their life away on addictions. It is simply not attractive and thus, not many people would want to be with someone with an extreme problem like that.
An unfortunate reason for a breakup, physical disabilities, also occurs at times. This can range from a paralyzing accident to impotence and infertility. To some people, having children is the most important priority in their adult life. Having a partner whom is unable to have children can very much hinder a relationship.