It’s not about taking it seriously. The meme wants to be a technically correct-meme, where a thing fulfills another things definition and thereby could be deemed the other thing - which creates the absurdity the meme lives off of. But in order for that kind of humour, there cannot be obvious holes in the logic of the joke and these obvious holes are very present in this meme.
Its supposed to be absurd, taking it seriously makes the already bad joke even worse
It’s not about taking it seriously. The meme wants to be a technically correct-meme, where a thing fulfills another things definition and thereby could be deemed the other thing - which creates the absurdity the meme lives off of. But in order for that kind of humour, there cannot be obvious holes in the logic of the joke and these obvious holes are very present in this meme.
Any maths joke of this type will have obvious holes in it, that’s just how maths works