Oblivious.

I was walking Bob the Dog the other evening. As the sun bade farewell and the sky overhead darkened, I looked to the North, where the distant hills were backlit by the bright afterglow of the sunset.
That afterglow created a strange illusion; the hills appeared to be distant trees with the light shining through the branches. In reality, it was the lights from some of the homes on the hill that, for a moment, had the same colour and brightness as the light in the sky, fooling my eyes and making me "see" a natural, rather than man-made, vista.
As the light departed and night fell, the truth was revealed. 
Bob walked on, oblivious to the deception.