You start out with a young colt, a bit stubborn and totally untrained. You get them started and then think about selling them. That is the business we are in. But you keep riding and training as you get organized to sell and then by the time the For Sale sign goes up you are inevitably thinking, "I'd kind of like to keep this one".
It's hard to let them go when you see them coming along so nicely and showing more potential all the time. You can only train and show so many senior horses. It's tough to manage more than a couple in limited aged events - it just gets very busy. And honestly, that isn't what you've been developing him for.
But it's hard to say goodbye and hand over the reins. Will the new owner treat him well? Will he behave and be a good hand? Will you get to see him again?