Before I started tutoring I believed that anyone can learn first year math and science if only they put in the time and effort.

Weirdly, I had the exact opposite conversion via tutoring, where "anyone" = "college students."

EDIT: I should clarify, I was a mediocre tutor. However, the head of the tutoring center was incredible. He regularly had people who were failing college algebra and science for non-majors and turned them into chemistry majors. In the sessions where he tried to mentor me, my students were obviously learning more than when I was by myself.