Find out about what? Masturbation?
I don't know how it is for women, but you don't have to be told how to masturbate. Maybe how to do it in a way that doesn't cause scabs, but for men masturbation is the simplest, most obvious thing in the world.
I mean, it is a natural thing to rub a spot that feels good getting rubbed. When I first figured that out, I hadn't quite learned to have any modesty or where other people's boundaries were. I was told by my mother to go do it in my room, with the door closed, and to wash my hands when I was done. Oh, okay. This is private. Gotcha. It was a long time before I tried to put anything in there instead just applying friction or pressure to my vulva.
My first orgasms came from humping the mattress. I didn't understand the contractions, and they terrified me. I thought I broke my vagina! I was too embarassed to tell anyone. I mean, who ever heard of a broken vagina?! How could I possibly get my mother to advise me? She said we could talk about anything, but we were insanely religious. I wasn't sure what I was doing was in keeping with the Commandments, but it was a life-long compulsion. I couldn't stop myself. At least my mother, who was also a feminist and a hippie, had told me masturbation was a good, wholesome activity, but I still didn't want to tell her I broke my only vagina! And what kind of doctor do you tell about it? No way was I going to my GP who knew my mother! But eventually the weird spasms subsided, and I would go back to humping the bed because it felt great.
Discussing this with men has yielded the information that lots of men start out humping the bed too. Quite a few told me that just like it took forever to occur to me to insert anything, they too needed social collaboration to come up with the idea to stroke, rather than to just hump, and most of them never returned to humping.
So. Imagine that a young dude is bathing himself, and discovers his erection. Imagine he continues bathing and finds out how lovely it feels to touch it, or hold it under running water, or push on it. Imagine he shares the bathroom with family and an elder catches him, shames him for playing with it. Might he never touch it again?
I come from sex positive parents. I was never told anything was dirty or shameful. I was told to read the Song of Solomon, and taught that sexual exploration is a beautiful, holy, sacred thing to be explored with my life partner only. I was told that turning my urges on myself and masturbating was wholesome, healthy, and would prepare me for a good sexual connection with my future life partner, as God intended. I was told it wasn't shameful, just very private. But it was my friends who opened my mind to the idea of shoving objects up in there. Without socialization, I may have come to that conclusion on my own, but maybe not. My closest friends came from socially moderate, left-leaning parents like mine. Our parents were friends. What if my friends were uptight, and wouldn't talk about these topics with me?
So imagine our hypothetical young dude has a sex-negative upbringing, and the urge to make his dick feel good never becomes stronger than the shame instilled in him. Imagine his friends all feel the same way, or pretend to. Imagine they make jokes that make jerking off sound shameful, just like his parents said. Is he ever going to masturbate? No. Not until his paradigms shift. And once he becomes sexually active, he may just never feel the need, having never developed the habit heretofore. Yeah, he's going to be in the minority, but he could be out there.