There is always some terrible deed we have done in our past, which keeps us haunting in the middle of the nights. No matter how many nights pass, it keeps coming some night or the other. Some nights it doesn't let you sleep and some nights it awakens you abruptly with a thumping heart. All you can do is to wait for the time to pass by until you feel a little, only little better and you close your eyes shut, and again like every other night, try to get over it.