>>112510165The appeal of /ss/ is simple nostalgic wish fulfillment: Everyone fantasizes about how moments in their life might've play out if they'd had foresight - what they'd have done differently if they'd known then what they know now. /ss/ is just a facet of that same fantasy.
Most guys had at least one experience growing up where they received a lot of attention and affection (usually innocent or at least not deliberately sexual in intent) from an older girl/woman - be it a babysitter hanging out with you, a teacher doting on you, a neighborhood girl teasing you, or what-have-you. And 10, 15, 20 years later guys find themselves wistfully thinking back fantasizing about that time they were sitting in their babysitter's lap playing videogames or that time they stayed after class with the teacher, or that time the neighbor girl was bullying them and how it might have played out differently if they'd known all the stuff about girls and sex that they know now