This does not surprise me. Because in my head, Neville's grandmother bears a striking philosophical resemblance to Auntie Mame, and therefore taught him jazz piano, swing dancing, and how to mix a perfect martini.

And he's good at all of them, only nobody at Hogwarts knows because who else in the wizarding world but Grandma Longbottom cares about jazz and swing?

Lots of people probably care about martinis, but the kids are all too young to drink, and not really rebellious in that sort of way.