Thank you folks for all your thoughtful responses, this has been much more illuminating that I had guessed!
I'm wondering if this dual thought process is the fundamental reason why women tend to find porn upsetting:
That a guy looks at it, can actually wonder what it'd be like, and then put it away and say it is completely meaningless to them, but a women, when she wonders what something is like, is much more likely to actually give it a whirl (edited to add: ), and extrapolates that a man would be the same way.
My SO wondering what some other woman would be like sexually would be what actually gets my panties in a wad about porn.
If I get to the point where I spend significant amounts of time imagining what something would be like, well, I have to tell you I'm likely to try to find out. Whether it's sexual or not (except for that unassisted flying fantasy).
. Maybe that's why I'm not really into porn (and perhaps for other women as well), because it's not gonna happen, so it's kinda a waste of time (with a few exceptions, *blush*).
If for instance I start subscribing to a travel magazine (because I love travel even though I can't afford it), if I keep reading those articles and looking at those glorious pictures, chances are I'm going to find a way to do some kind of travel.