Dreams that don't come true?

I'm sure I'm not the only person to experience this although I will tell you mine. Have you ever had a dream say to play for a soccer or football club but your actually no good. I'll be honest without being realistic, I want to be an AFL player when I grow up, I am 13 years old, I know I'm good without being arrogant but I know also that you have to be the best player to get to the AFL. What should I do to make this dream come true? No silly replys like you can't make the AFL thank you.