I try not to pay attention to the obvious and try to delve into details.
That's exactly why I recommend an exercise - next time you travel, try to catch yourself thinking "well, there's nothing to photograph here". Photograph it and look at the photo in a couple of days. It's very likely that these are exactly the photos that will speak about your journey.
It seems to me that an interesting brain feature is to blame - after some time it begins to adapt to the environment and perceive new impressions as something proper. This is done to save resources. Otherwise too much information would come in that needs to be processed and laid out.
The process of "parsing and storing" information, by the way, happens during sleep, so I highly recommend sleeping as much as possible during travels.
As an example - look at this photo from Paris, which I took exactly when there was "nothing" to photograph.
And this photo can say more about the city than the Eiffel Tower. Shutters on windows, graffiti, tables on the street, sky. This is exactly what today's Paris is.
For comparison - Prague.
Cobblestones, relief and universal grunge.
It's precisely interesting thoughts about uninteresting photos that make a person's worldview.