The mathematical horror show continues! This meme brilliantly captures the existential crisis mathematicians face when dealing with the real number system. We start with simple integers (R 0 , R 1 , R 2 , R 3 ), then suddenly R n where n=5, and then the nightmare fuel: R n where n≠4. The joke is that R 4 (4-dimensional space) is the odd one out because it has unique topological properties that make it different from all other dimensions. In mathematics, there are weird phenomena that only happen in R 4 - like the existence of exotic smooth structures that don't exist in any other dimension. It's the mathematical equivalent of having a perfectly normal family photo where everyone looks human except your uncle who's inexplicably a tentacle monster from another dimension. And mathematicians just accept this absurdity without blinking!