Nothing specifically.
It went like: studying string compactifications after ACM suggested Duff's article on $G_2$ holonomy but then to understand that I had to read complex geometry, got sidetracked by studying black hole microstate counting and mock modular forms and then heterotic string theory (most compactifications are based on these nowadays), and then to understand $E_8$ stuff, some group rep theory (mostly Dynkin diagram stuff), then a bit of GUTs, and now back to actual CY compactification...