I learned why 'out riding alone' is an oxymoron: An equestrian is never alone is always sensing the other being the mysterious but also understandable living being that is the horse.
It's part of a writer's profession as it's part of a spy's profession to prey on the community to which he's attached to take away information - often in secret - and to translate that into intelligence for his masters whether it's his readership or his spy masters. And I think that both professions are perhaps rather lonely.