Humans now have ridden horses for thousands of years. They have also milked them, eaten them, and bled them. People have gone to war on horses and traveled long distances during peaceful times on horses. Horses have facilitated the construction of cultures and the spread of ideas and technologies. They have done all of these things simply because they are hardy and they provide rapid, highly available transport.
Even today, cultures and communities exist around horses. Why is it that some little girls and boys seem to be born with no other wish than to ride a horse? We have a connection to horses and they to us. Obviously, we have changed them over the last 6,000 years, making them taller and smaller, faster and slower, stronger and more delicate than their wild predecessors . However, they have changed us as much, if not more. They spread our ideas, they won our wars, they provided us with food, beverage, and companionship. Without the horse, we would not be the humans we are.