I would say anywhere from 10 to 20 minutes depending on how stiff your horse is and the weather conditions. If it is really hot, don't waste a whole 20 minutes letting him stretch because his muscles will already be loose. But if it is cold out I would definitely spend at least 20 minutes letting him stretch at the walk trot and canter before asking him to do anything strenuous.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.