Could creating your character be likened to an artist creating a sculpture? I believe that character is not something that just happens by itself, any more than a chisel can create a work of art without the hand of an artist guiding it. In both instances, a conscious decision for a specific outcome has been made. A conscious process is at work. Character is the result of hundreds and hundreds of choices you make that gradually turn who you are, at any given moment, into who you want to be. If that decision-making process is not present, you will still be somebody. You will still be alive, but may have a personality rather than a character.
Character is not something you were born with and can't change like your fingerprint. In fact, because you weren't born with it, it is something that you must take responsibility for creating. I don't believe that adversity by itself builds character and I certainly don't think that success erodes it. Character is built by how you respond to what happens in your life, whether it's winning every game or losing every game, getting rich or dealing with hard times.
You build character out of certain qualities that you must create and diligently nurture within yourself, just like you would plant and water a seed or gather wood and build a campfire.
You've got to look for those things in your heart and in your gut. You've got to chisel away in order to find them, just like chiseling away the rock in order to create the sculpture that has previously existed only in your imagination.
But do you want to know the really amazing thing about character? If you are sincerely committed to making yourself into the person you want to be, you'll not only create those qualities, but you'll continually strengthen them. And you will recreate them in abundance even as you are drawing on them every day of your life. Just like the burning bush in the biblical book of Exodus, the bush burned but the flames did not consume it. Character sustains itself and nurtures itself even as it is being put to work, tested, and challenged. And once character is formed, it will serve as a solid, lasting foundation upon which to build the life you desire.