I was in my mid-teens when I had heard of them, I'm pretty sure. They kind of weirded me out back then. I vaguely remember my friend jokingly insulting another one of my friends and not knowing what the world "dildo" meant when he said it.
I was never told about them as a child, but I figured out quickly when my father commented on a blue jelly dildo that was in a box my friend was carrying for a neighbor, asking if we had used it, which we hadn't. I think I was 12 at the time. I didn't learn all that much more about them until my first visit to Spencer's and I learned the most when I visited edenfantasys for the first time.