Flying always feels different after sunset. Isolated, elsewhere, in orbit instead of just above. My world becomes the plane and the plane is the entire world. Cities and farmland and lakes and railway lines, they are real. But the twinkly lights below me, the reflection of a desert sky, I find it difficult to believe that there are people down there. The black land below me gains a sheen of unreality, a world between darkness and dreams.
When you are flying at night, darkness is the enemy. Darkness could be an isolated area but it might be cloud or worse, a mountain rising above your height, obscuring your view. However unreal it may feel, that darkness may be very solid and closer than you think.
At the age of forty, I finally have an excuse for being afraid of the dark.