Because someone said something along the lines that someone still had time to grow, so age was brought up to let others know that they will either continue growing, or they are done. In mostly everyone here's case, they will continue to grow, but for me, Adrena, kidag, etc. we will not.
So did I in high school. I was 6'2" and 140 or so pounds during that time also. In college I stopped all athletics basically, and I'm not 6'2" and 195 pounds.