I am going to create my own manga series. As my favorite orator said, "Don't waste your time with jealousy, sometimes your ahead, sometimes you're behind. The race is long, and in the end it's only with you're self" -Baz Luhrmann.
For myself, I believe that there is no certainty for anything in life. That's why in the court of law, you cannot prove a person's guilty beyond a "Reasonable Doubt" conviction.
But for the bigger picture, it's simple. When I die, I wish that my life had value. That is to say, for how many people we encounter a day, to have a positive effect and outcome from someone gives one value to their life.