I just don't understand

I'm nearly 40 and at such point in my life that I'm trying to face and close any and all issues I avoided / "forgot" / could not find the time and or strength to deal with. So, here's one of them I never spoke to anyone about before: How is it possible for a five year old boy brought up in a normal, Christian family, back in the days of no computer nor internet, no DVDs or VCRs, only two channels of black-and-white TV and no "adult magazines" or anything of the sort available to implant such notions, to fill notebook after notebook with drawings of naked women in sado-masochistic poses/scenes. How is it possible for his head to be filled with such "concepts" so he'd spend hours staring at a ceiling, imagining such scenarios? The Bible speaks of evil spirit possessions. I don't believe in reincarnation, much less of retantion of memories of some past life. Suppressed memories of someone's evil deeds? I have not a single recollection of anything related. But I know that before reaching that age I was hospitalized many times, sometimes for weeks and longer, far away from home and anyone familiar. Supposedly, one of the nurses liked me so much she would take me home for weekends; or so I've been told. This is the only setting I can think of where I would be exposed to strangers. But I remember nothing. But I remember which way my mind wondered since that time, long before I knew anything about sexuality, not to mention it's different avenues. Help, anyone?