Jaabir ibn Abdullah narrated that Allaah's Messenger (peace be upon him) said, "On the Day of Resurrection when people who have suffered affliction are given their reward, those who are healthy will wish their skins had been cut to pieces with scissors when they were in the world."
In other words, when people see how much reward is given to those who suffered in life, they will wish that they had suffered terribly, so that it might become a cause for forgiveness for them in the Hereafter. SubhaanAllaah. Whatever pain we suffer in this life is not in vain. It is not wasted. Allaah sees our suffering and will compensate us more than we can imagine, as long as we are patient and keep faith in Him.