[kgwgk]

As far as weird edges go, that one is really, really mild. It may even be considered a good idea!

For people interested in weirder things, check The R Inferno (I think it's somewhat outdated by now, though):

https://www.burns-stat.com/documents/books/the-r-inferno/

[jsmith99]

That book isn't so much about R weirdness. It's more about teaching data scientists to consider the implications of practices like copying a huge table in memory on every loop iteration.