I'm gonna be honest, I'd only ever heard the "nǐ hǎo nyan" jingle in that one brony fan-animation of Derpy Hooves doing the dance, where there's a random weird bit in the middle implying that Derpy is inviting Doctor Whooves to make a little pony sex tape. And then in the years after I watched that brony fan-animation, the jingle would keep randomly popping back into my head, without me remembering where I first heard it, and for some reason never thinking to look into either where I first heard the jingle, or where it originally came from... And now, serendipitously, I stumbled upon the original source.
And with that I have gotten closure about yet another random weeb thing from my childhood that I didn't even realize I wanted closure about.
"Deculture" is basically an alien slang term for awesome, at that point of the fictional timeline. There's a lot more to it than that but it's kinda spoilers hehe.
OG Macross series is fun but a bit draggy, honestly I'd recommend you watch the movie Do You Remember Love first since that is basically the baseline story all the other ones call back to (and it's all gorgeous cell shaded animation to boot), and then you can decide to plunge into the rest of the shows if you like or pick-and-choose the shows that interest you.
Me explaining the Macross shows really badly:
OG Macross - What if Gundam but instead of psychic powers you had to beat the Space Nazis with Pop music?
Do You Remember Love - Men are from Mars and Women are from Venus
Macross Plus - What if Hatsune Miku hijacked the military industrial complex and the only way to stop her was to get into an F-22 and shoot down all her drones
Macross 7 - Space John Lennon defeats energy vampires with the power of pacifism and rock and roll
Macross Zero - What if, like, Shaman Idols and Pop Idols were the same thing, huh? Also War Bad Environmentalism Good Takes a massive rip from a bong (This is an OVA prequel series that's really not all that related to the main plot of the shows but then Macross Frontier makes it important so...)
Macross Frontier - What if Ariana Grande hired Blackwater to stop the Iraq War?
Macross Delta - Our crack team of Idol Commandos are going to do whatever it takes to stop a bunch of Alt-Right Emoboys from mind-controlling the universe through Opera, with the power of free market capitalism and pop music
Do you Remember Love is basically a movie retelling of the events of the tv series, except that things happen quite differently so... (when asked, the creator of the franchise basically said that all the shows are canon in-universe dramatizations of historical events and that we the audience are free to decide what's canon, which is both based and lazy lol) Frontier and Delta also have movie series that retell the events of their tv shows in a different way, and they're pretty good, although I think in those cases I'd recommend the tv shows first.
If you decide that you're not going to watch all of them (OG and 7 are really long shows at like 50+ episodes each) the highlights from the series I'd recommend are: DYRL, Plus and Frontier.
Edit: Oh wait I need to warn you there are parts of DYRL that really didn't age well wrt gender politics