My memory is a bit fuzzy but I think I was looking for random anime art to get inspiration from when I ran across an Revolutionary Girl Utena screen shot. I was fascinated by the style and aesthetic but I still didn't watch it for a long time until I saw someone posting about RGU on tumblr.
EDIT: I just remembered it was actually an AMV for a song by J^p^n. It
was after that that I looked for more images of the characters for
inspiration