I also have other horses to ride so my old man doesn't need to do the "heavy lifting" anymore. I still enjoy riding him, but I don't have to so that puts me in a position to ride him to keep him fit and otherwise let him be. Funny story... A friend of mine has an ancient mare. I would say mid 30s and she's been a lesson horse forever. So the day she retired was the day she was saddled up and bucked a rider off. A behavior she had never done, ever. Chiro came, she was fine. Vet came out for shots, clean bill of health. She waited a few days put an experienced rider on her and KABOOM to the moon. So, she's retired.