However, a lot of non-native speakers of a language (including myself with Japanese, though I try not to operate like this) remember rarer words by associating them with their equivalents in the person’s native tongue, as opposed to associating them with their base meaning. When I hear 事件 (jiken), a pretty common word, I don’t think “event/case/accident”, I think “some sort of occurrence where there’s something kinda bad or urgent happening and maybe someone should think about resolving it”, but when I hear… I don’t know, 撮影 (satsuei), I think “photoshoot” (and not “act or instance of one or more people with a camera taking pictures of someone probably posing in a setting that’s probably brightly lit”, like I should). That means when I encounter the word 撮影 during translating, I default to “photoshoot” and try to fit that noun into the sentence instinctively, rather than thinking of the sentence’s meaning as a whole.

To me, it seems native English speakers learning Japanese have started having “melancholy” as their primary internal definition of 憂鬱 over “depression”.

Another Haruhi-related one-of-these-things is the word “disappearance” for 消失. The song 初音ミクの消失 (now typically translated as “The Disappearance of Hatsune Miku”) used to be known as both “The Disappearance of Miku Hatsune” and “The Vanishment of Miku Hatsune”. In fact, even 涼宮ハルヒの消失 was known as “The Vanishment of Haruhi Suzumiya” occasionally.

However, ever since the Disappearance movie aired, I haven’t seen “vanishment” at all for either of them.

I don’t have any true understanding of Japanese so I can’t comment on the implication of 憂鬱 in terms of severity and duration, which I consider the two key points of differentiation. Interestingly enough I came across a word that was new to me that was suggested as a synonym for 憂鬱 by the Chinese Wikipedia entry – lugubriousness, which is defined by Merriam-Webster as “full of sadness or sorrow : very sad especially in an exaggerated or insincere way.” Imagine what the world would be like it “The Lugubriousness of Haruhi Suzumiya” had been chosen instead.