7th grade in middle school when I told my (mostly white & christian) classmates on the bus to school that I didn't believe in God and they all branded me a terrorist because that's all we heard about politically in the years post 9/11.
Gotta thank them though because that pushed me into being politically aware (although some of you will be shocked to learn I was a /b/ poster all throughout middle school and up until like Freshman/Sophomore year of HS when Obama was running; to me this is not shocking because obviously 99% of /b/ posters during that era and maybe even now are middle schoolers)
Wasn't a true leftist (read: more left than most liberal) until 10th grade or so, coinciding with my first few jobs lol