What makes people regret their life when they are on the verge of death is because there is something that they didn't do in their life. Is it because they are yet to see what they want to see in the world that is yet to hit the peak of its success. This Universe is filled with all types of beings that are yet to be found and they will never know that they are on the verge of death when they walk outside of the door. They are not realizing that the world is a dangerous place and so they will now know that they will be the ones to make sure that they can live their life to the fullest.