Is there a word to describe nostalgia for things that never existed? For example, a 1950s-style diner is supposed to reconstruct a cultural archetype, but there never existed such a diner. John Wayne characters are similar, he usually plays a cowboy-type, but no heroic cowboy ever really existed.
Nostalgia is still the correct word, because it being related to some personal association to a historic place (even if it is false). For example, with pirates, you might see a guy with an eye-patch and a parrot and think "Oh! A pirate.". However, if someone who had never seen movies or read books with pirates with those characteristics, then they would associate it with pirates.
Another example could be thinking about home. If you grew up in a coastal city, you might think that the smell of fish smells like home. In reality, most homes or cities don't smell like fish. You would still be feeling nostalgic if you related the smell of fish to your hometown.
I hope this helps.
"Idealization" can also be used for this concept. We tend to "idealize" something from our past or our history that may be just a fantasy version of that person, place, thing or time.
How about pastiche?
- a literary, musical, or artistic piece consisting wholly or chiefly of motifs or techniques borrowed from one or more sources.
- an incongruous combination of materials, forms, motifs, etc., taken from different sources; hodgepodge.
In urban planning, a pastiche is used to refer to neighborhoods as imitations of building styles as conceived by major planners. Many post-war European neighborhoods can in this way be described as pastiches from planners like Le Corbusier or Ebenezer Howard. Alain de Botton describes pastiche as "an unconvincing reproduction of the styles of the past."
There is no single English word to express this concept. As usual in such cases, try broadening your cast; describe why the nostalgia was false. Did the subject have no actual memory? Was he lying? Romanticizing something that doesn't deserve it? That's the way to go.
I have a single word for what you describe: fantasy. Or how about phantasm?
Sometimes we need to turn to other languages:
"Sehnsucht might be one word you are looking for. It's homesickness for the life you wish you had."