My earliest memory is when I was around 4 and I was riding my bike (with one training wheel) indoors while my younger brother, about a year and a half younger than me, was watching and pulling things out of the way. It's a weird memory because it's in grey and it looks like a snapshot in my mind's eye but I can think of much more than just the picture shows. I remember I was thinking that I hoped my mother wouldn't notice tire tracks.
What was memorable about it was that my brother and I were alone but still doing activities together, whether or not our mother had expressly forbidden said activity. That is how I know I'm a different person now because my brother and I would never do something that stupid. In the time it would take for my brother and I to collaborate and consider such a plan, we would end up in an argument resulting in us either fighting or leaving to cool off.
It's interesting how you said your memory is in greyscale and looks like a snapshot, yet you remember more than just that visual representation. It reminds me of how Professor Kotovsky said that a lot of our visual memories are fabricated from what we remember experiencing at the time. It is much like how he had us envision the last time we went swimming, and many of us realized that our "memory" had ourselves pictured in it, though this would not be possible if memories were only stored visually.
I have a lot of memories similar to this in that I can see myself in the memory and can picture the circumstances in the entire house instead of just what I would have been able to see. I think it's also interesting that both of our memories involve sibling relationships at a very young age. It seems that my memory about how I interacted with other people is more reliable than my visual memory. I know that it's impossible for me to remember exactly what everything looked like and I know that my visual memories are definitely built off of photographs, but I'm pretty sure that my memory of my relationship with my brother is accurate and only based on my experiences.
I agree with the idea that so many of our memories don't seem to occur as a motion picture, but as a couple of very vivid snapshots. The actions that impact you and influence who you are are the ones that first come to mind when you look back. At the same time, I think these memories form some kind of wake up alarm within you that helps turn your life around and makes you a stronger person. In this case, your memory with riding a bike in your house when you weren't allowed to could help influence you to avoid disobeying a rule or think ahead if you are put into a serious situation.