Not that many exes TBH, only one I know anything about now is still in education. A bloody good teacher who AFAIK has stayed in the classroom rather than head for senior leadership.
Of my closest school mates, we’ve all reached vaguely the same level in our chosen careers but none are super high flyers (more to do with our attitudes rather than aptitudes I would say – there’s more to life than work). One was a County Archaeologist and is now curator of a museum, one made a fair chunk of cash working in IT during the boom years, and one became a physicist working for the MoD but can’t really talk about what he does (knowing his area of specialism I kind of get that).
Oddly (or not given that I teach in the city I grew up in) I now work in a school with my cousin, and two people I was at school with (one of whom is now my deputy).