That’s far from exclusive to interior design. Any designer in every discipline will be familiar with that notion, regardless of it being interior design, industrial design, graphic design, …
“Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible” — Donald A. Norman, The Design of Everyday Things (1988)
I was about to recommend an episode or two, but it's an institution at this point. If you have a reasoned opinion about flags, there's a reasonably good chance it's because you saw or heard Roman Mars talk about vexillology.
https://www.ted.com/talks/roman_mars_why_city_flags_may_be_t...
“Good design is actually a lot harder to notice than poor design, in part because good designs fit our needs so well that the design is invisible” — Donald A. Norman, The Design of Everyday Things (1988)