Hello Kiddo,
When we see something happen, we use our eyes to remember it in our brain. This is called our "eyewitness memory". But, just because we saw something, it doesn't mean we will always remember it exactly as it happened.
Our brains can be tricky sometimes when we try to remember things. It is like playing a game of telephone. You tell your friend a message, and your friend tells someone else, and they tell someone else. By the time the message gets to the last person, it might be different than how you said it.
Our brains are kind of like this game, so sometimes we don't remember things exactly how they happened. This is why people can sometimes disagree on what they saw happen.
There are also some things that can make it harder for us to remember things. For example, if we are really scared or stressed when we see something happen, we might not remember all the details.
So, when we hear about something that happened from someone who saw it, we should remember that they might not be remembering everything exactly as it happened. Sometimes, it's best to have more than one person's eyewitness memory to get a better idea of what really happened.
I hope that helps you understand eyewitness memory, Kiddo.