Why did you break up?

If you delve into your breakups, you will easily find that the root cause of each one was unfulfilled expectations on your part as well as on the part of the other. You expected one behavior and attitude, but got something different in fact, and it doesn't matter in what areas - whether it's sex, the amount of attention, common interests, children, or money. So what you received eventually did not coincide with your ideas of how it should be or how you would like it to be. The same happened with the other's expectations though.