In the following column:
it is suggested that mounting a horse from the left was based on where swords were worn, etc.
This undoubtably is a factor but it misses a much more basic reason. Most people are right handed. If you are right handed, just try to get on a horse from the right side and see what happens. Right Handers typically do heavy work with the left hand/foot (even if the right arm is stronger) when they need to use the other hand for fine work (reaching, grasping). Watch a right handed high jumper, basketball player, etc and you will see he always pushes off from the left foot when he jumps. Try to jump on a horse from the right side by pushing off with your left foot and see what happens. You will look both like and at a horses ass.