>>901
Logic and model theory are a bit weird in the sense that they're mostly disconnected from the rest of the math world despite seeming fundamental. Of course I am neither a logician or set theorist so my view may be biased but it is interesting how both camps often know very little about the other side. And then there's stuff like algebraic geometry in its formulation by grothendieck that seemingly required inventing/appealing grothendieck universes just to define some things rigorously. Turns out it wasn't necessary (see the stacks project, there's extensive discussion around size issues).