As soon as I see Bertha’s rear end backing down the tailgate towards me, I think there has been some mistake. They told me they would find a nice quiet mare, given that I have never been riding before. Advancing upon me are the towering bay buttocks of the biggest horse I have ever seen. In a daze, I mount the stool, held for me by Di Grisselle, joint master, shove one foot in the stirrup and try to swing myself over.