What age to become a great rider? Unrealistic goal?

YOU ARE NEVER TO OLD TO BECOME A GREAT RIDER!!! I have a really good friend who started out at nothing and have come up to Mc clay level. All it takes is dedication and practice and a LOVE for what you are doing. And riding is an amazing way to relieve stress and work together as a team with an animal that will become your best friend. My horse is my best friend and has been for a long time!! Trust me you don't have to start young to become great! Trust me it definitely is not unrealistic!! GOOD LUCK!