Looking around at girls.
Noting with clinical curiosity that I liked tits, tummies and asses.
Observing that girls who were bigger had more of the aforementioned.
Taking an embarrasingly long time to realise that websites such as this exist, and have content I enjoy on them.
I took a detour via Charlie and the Chocolate Factory (book, not film) to realise that even if a girl didn't precisely fit the desired specifications there were cartoonish and unrealistic ways to change that. That lead me to favour /inf.
I love talking about this so please, if you want to reply with questions, I'd love to field them.