Every now and then a phrase pops into my head and won’t leave until I write it down or tell it to someone else.
One day the little voice in my head suggested putting “Didn’t” before the classic series of maths textbooks, Graduate Texts in Mathematics.
So I found a cover of a GTIM book, stuck “Didn’t” on the front and changed the title to an in-joke about not understanding category theory, and was happy with my life.
![A Springer book cover: Didn't Graduate Texts in Mathematics. Sandy McLane? When All The Arrows Mean It's Obvious](https://aperiodical.com/wp-content/uploads/2022/05/When-All-The-Arrows-Mean-It-s-Obvious1.png)
But then I thought that it would make sense to make a whole series of these, so I spent a couple of hours making a meme generator.
And then I tooted and tweeted it.
It looks like this struck a chord with anyone else who’s ever seen one of these books and been like “🤷” – the tweet got just over 2,000 likes, and a tonne of replies giving variations on the format.
Here are some I particularly liked:
![Thea Retician: Machine learning is just linear algebra. Or linear regression. One of those.](https://aperiodical.com/wp-content/uploads/2022/05/FS6JhfOWIAEARzT.jpeg)
![Antoine-Laurent de Lavoisier, George Polyá: How to dissolve it.](https://aperiodical.com/wp-content/uploads/2022/05/FTEMEmMWYAcjE1Q.png)
![Don Knoth : This font doesn't look quite right? (written in a serif font, unlike the other covers)](https://aperiodical.com/wp-content/uploads/2022/05/FS4GJwOXsAIw-KM.png)
![Isaac Newton: I probably should have published this 20 years ago](https://aperiodical.com/wp-content/uploads/2022/05/FS6bETlUAAAG_xA.png)
![C.F. Gauß: I probably already knew the thing you say you proved](https://aperiodical.com/wp-content/uploads/2022/05/FS53uM9UsAAXvqg.png)
![S. Banach & A. Tarski: Please do not reproduce this textbook](https://aperiodical.com/wp-content/uploads/2022/05/FS6TiYAXEAE-9LU.jpeg)
![Rudin or someone: A fifty quid doorstop](https://aperiodical.com/wp-content/uploads/2022/05/FS32zAhWUAUp0wD.png)
![Bryan Konrad: The diagram really does commute, or, I checked all the signs so you don't have to](https://aperiodical.com/wp-content/uploads/2022/05/FS6qk9rUAAAzV3w.png)
![Graham Priest: What's Disjunctive syllogism, again? (Above a dozen lines of logical connectives)](https://aperiodical.com/wp-content/uploads/2022/05/FS6E2-XXsAEcKpH.png)
![Kurt Gödel: Logic - incomplete notes](https://aperiodical.com/wp-content/uploads/2022/05/FS6LzUIX0AEfIh1-684x1024.jpeg)
![Analytic Numb R. Theorist: No, the bound is not effective](https://aperiodical.com/wp-content/uploads/2022/05/FS8cUBZXEAAnUI4.png)
![Cohen O. Mology: Because differential topology wasn't hard enough](https://aperiodical.com/wp-content/uploads/2022/05/FS9wTQIXwAAAomP.jpeg)
![A. Analysis: Where every constant is one](https://aperiodical.com/wp-content/uploads/2022/05/FS8s6XEaIAAxPgm.jpeg)
![No Clues: A first course in algebraic topology (for professional algebraic topologists)](https://aperiodical.com/wp-content/uploads/2022/05/FS52FHqXsAEmCbu.png)
![Prominent Mathematician: If I hurt your friends I will still be invited to conferences](https://aperiodical.com/wp-content/uploads/2022/05/FS6IikUWAAsVtO0.png)
And this version by Davide Castelvecchi currently has just under 20,000 likes!
![Introduction to that thing: but only for people who already know it](https://aperiodical.com/wp-content/uploads/2022/05/FTBdMZ5XsAAeq8C.png)
So that was a good bit of fun.
Pal or Halmos?
A Naïve Hilbert Space Problem Book