This is a great description of instrument flying. Most of the time, you don't suffer from spacial disorientation, but when you do it is a very very powerful force within you. You have to recognize that you are disoriented and have the discipline to understand that the instruments are correct and know that your brain is screaming lies to you. To take it a step further, you also have to be able to do this when you have a single instrument failure or multiple instrument failures. The failed instruments may all also be telling you a lie. It's not easy and those who aren't proficient are in serious trouble.So, with the lack of a horizon, and the loss of that visual reference, it has to be created. But at the same time, the acceleration (G force) of flight is creating signals in our inner ear that scream “you’re leaning, you’re falling” to our brain. It takes a great deal of discipline, as well as a great deal of practice, to ignore your basic instinct for survival, which is screaming at you, that you must respond to it, and trust your instruments instead.