Used to be into greek mythology. In one of the library books there was pics of boys in short togas and I got excited over it. Then I watched this program about all the gay stuff about ancient greece the victorians hid away, including this cup with scenes of boys doing it and I knew I really wanted to be one of the boys
About the same time (age 12 i think) I had a cute french exchange friend over and I wanted him to do that to me. He was a year older and wouldn't because he knew it was gay, and that was the first time I found out that not all boys were up for it and defined myself as 'gay'.