If you don't think that you have anything in common with your significant other, you might be right, or you might not be thinking of some of the deeper values that you two share together.
No matter how long you and your significant other have been together, there will always be a conversation that is slightly awkward between the two of you, but you know you have to have it.
There are so many reasons why a couple stays together, and it varies from relationship-to-relationship, what a good reason is for one could be a terrible reason for another. All the same, the reason why a couple decides to break up is just as varying.
Committing to someone forever seems terrifying to some people. They can commit to a career, to friends, to an entire lifestyle, but to another person? No way.