The sky is the limit

I really do not know why this is happening, but whenever on the plane my brain starts to work extra-intensively. I may spend a week on the beach with 7 must-read inspiring books but the best ideas come on my way back home, on the plane. Is it the change on pressure in the cabin? Or the lack of oxygen maybe. I really don't get it but if I had some frequent flyer status and was able to fly more often I would have my book and serveral articles already written. It truly amazes me because it is definitely not the case of free time - I may have more of it at home and I am not so productive. Maybe it is the case of the views I experince during the flight? Maybe when you see that the sky is the limit, you act accordingly?:)