You don't have to lift a horse to take it with you, they move on their own (that's what makes them so useful), are domesticated and will follow you when properly handled.
Also, humans have been putting a type of chair on horses for some 2700 years, called a saddle, and sitting on that.
Also, humans have been putting a type of chair on horses for some 2700 years, called a saddle, and sitting on that.