I remember this quite distinctly. A boy who was maybe a year or two older than me and lived just up the road hit puberty before I did. He would quite often try to get me alone so we could do stuff. I did't really grasp the full nature of what was going on. Nothing too serious of course. But it's clear now that I wasn't so much a participant as someone for him to experiment with. I was too young too know.
However, I harbor exactly zero negative thoughts or feeling of animosity or anger about any of it. The kid in question was waaaaaay to young to know that what he was doing was wrong. No harm done.

On an interesting side-note, I chose never to tell either of the Therapists I have seen about this, as both seemed eager to find a "repressed" memory of "abuse" that would explain my aversion to sexuality.