Oh Right, My Muscles! - Stray Kids

Why Koreans care

The title's "아 맞다" (a matda, "oh right" / "I just remembered") is an everyday Korean interjection for suddenly recalling something you'd forgotten. Framing "내 근육" (nae geunyuk, "my muscles") as something Changbin had "forgotten" and now "remembers" is a small self-deprecating joke built on that stock conversational phrase, not a literal claim — a format a foreign viewer unfamiliar with the expression would likely miss.

In the Korean comments

Majority: several commenters simply find the moment endearing rather than reading anything into it, as in one top comment: "이게 뭐람…ㅋㅋㅋㅋㅋ개귀여워ㅠ" (roughly, "What even is this... lol, so cute"). Fandom: other comments pair praise with a reflexive reminder to ignore hate, a recurring pattern in idol-fan comment sections regardless of whether any specific criticism is visible in the clip itself: "승민이랑 창빈아, 항상 행복하고 악플은 무시해. 너희가 최고의 가수라는 걸 잊지 마" (roughly, "Seungmin, Changbin, always be happy and ignore the hate comments. Don't forget you're the best singers").

What the words mean

A foreign viewer might read the "ignore the hate comments" line and assume this cute clip provoked some specific backlash. In Korean fandom culture, telling idols to "악플은 무시해" (akpeul-eun musihae, "ignore the malicious comments") is a stock reassurance fans attach to almost any idol post, regardless of whether real criticism exists anywhere near it.