Why is the heart still particularly sad after the breakup and reconciliation?

After the breakup, and then the two of you now and good, why will be very sad, because you feel very sorry for her in the breakup of this period of time, there will be a sense of guilt in the heart, although it is said that now together, but you would rather not have that a past.

In the end, it is still a burden in your own heart, so if you feel still very sad, you should give more love to each other, so that the other party to feel. As long as two people are happy and happy together now, that's all that matters.