I 100% know what you mean. I am playing this game called Dark Souls. And When I begin to fall asleep, A fake Dark Souls world gets created into my mind and I am literally playing the game. I hit the enemy and it hits the character and he gets knocked back into an abyss and I died. And in BIG RED LETTERS IT SAYS: YOU DIED! And I respawn at a Bonfire and I go back to the same enemy and whoop its ass then fight a boss and cool orchestrated music plays in my head and....

yeeeaaahhhh....