I guess that would be my 12th grade AP English teacher. Before that point, I was dickering with comics, and he saw them and wanted to put them in the school paper; I wound up winning an award for them.
He just...seemed to be able to get people - pretty much everyone around him. It might have been more of a social intuition, but he got me thinking about literature in a new and different way, and made a huge impact on me on how I turned out as an adult.