system
apprehensive: I was going to fly alone. I felt a bit wary. 
human
I was flying alone, even though I had before, this particular time I felt wary.
human
Really? Why was that?
human
I think I felt concerned that the plane would crash or that something else bad might happen. 
human
Do you normally feel like that when you fly?
human
I do sometimes, but this time it was even more so.