For the most part, once up into the realms of commercial cruising altitudes, the terrain loses all interest. It becomes merely a map reader's curiosity - seeking out all those features you know are there, but which sometimes skulk in low contrast obscurity.
However I do envy those commercial pilots who get to cross the Himalayas and the Andes. Looking down on Everest and the like, maybe spying climbers on the ascent in much the same way as I might spot climbers on Snowdon. I find a strange fascination in the idea that those brave mountaineers, often cold, isolated and maybe fearing for their lives, will look up and see just a few thousand feet away, ordinary folk sitting in gin and tonic luxury, probably looking back at them, but just that bit too far away for eyes, or souls, to make contact.