Right samadhi means you have to be without mind, fully awake; in wakefulness, thoughts have to disappear. It is easy to fall asleep, to fall into a deep coma, in a kind of hysterical fit and be without mind; but that is falling below mind not transcending mind. Right samadhi is a transcendence: you go beyond mind, but you are fully alert, aware. Only then is samadhi right — when it grows in awareness and when awareness grows through it. When you become enlightened you have to be absolutely awakened; otherwise you missed at the last step.