Mr. Diggory.
Not very often. We had very different circles. Once he gave me some really useful pro-tips when I was stuck on an assignment and the library was about to close and you know? Most people would just outright ignore you and get on with their night but he actually stopped by to be nice.
I think maybe if we didn't have the House system at Hogwarts maybe it would have been easier to cross paths with more people, you know?