Now this is advice from somebody who doesn't have children....
In general early teens need to be made aware that life comes with disappointment and that we want it doesn't mean we have a shot at it.
Right or wrong, fair or unfair.
Being an Olympian, concert pianist or world famous spy, all of us have dreams.
I would keep that to myself right now and let him enjoy his youth.
But he does need to be taught about unfairness of life and dealing with emotional blows. In general not specifically this. One day a girl will break his heart too...guaranteed.
He'll need to deal with that also.