Horses have two sides to their brains: the left brain and the right brain. Each side of your horse’s brain is like a completely separate horse. You’ve got Lefty and you’ve got Righty. Horses hear, smell, think and react differently on each side of their brain. Whatever you do on one side of the horse, you have to do on the other. Just because you desensitize or sensitize your horse to pressure on one side of his body, it doesn’t mean that he will automatically understand what to do when you move to his other side. In order to have a well-balanced responsive horse, you have to act like you own two separate horses and train him as such.