If it's not it's got to be something like that, anyway. Mum said when we started Hogwarts that Professor McGonagall had a Personal Tragedy that left her teaching, or something, so she didn't start right out of school like Professor Siz, but it's been forever, anyway.

And yes, Professor Slughorn even taught Professor Dolohov, so he's been here even longer than the Headmistress. We could certainly include all the Heads of House, too, if we look up when they came here. Or anyone who's got more than 30 years (though that would also include Binns, technically).

I'm sure Lav would be happy to talk to Madam Hooch. Really, she's only that gruff on the outside. Pav says if you get to know her she's really quite, er, well, tolerant.