How powerful is the mind

I don't know what made me think of this exactly. But here it is.

When I was a kid, about 10 or so. 2 bad things happened to me. I remember when I'd start to feel anxious about them, I'd just remember "there are just 2 things I don't think about it." So I just don't think about it. The start of the story would pop in my head and I'd say, don't think about it, and I'd stop. I always remembered that I blocked out 2 things.

One of them was this story: my little brother and I were swimming at a hotel swimming pool. We always stayed in a hotel with water slides when we'd come to the city to go Christmas shopping. Anyway, I was a good swimmer and my little brother was just learning to swim. So we play a game, we inch along the edge of the swimming pool, I'm behind him, both our hands are holding the edge, my arms around his (make sense?). We go to the deep end. (there are no lifeguards in hotel swimming pools usually.) Anyway, there are some adults along the pool edge, so we can't just inch past them. We go around them, push out, and jump back in. We can't touch right? But it was basically like a little hop. Then there are about 3 adults next to each other. We try and hop around them, little brother panics, starts the drowning thing, clings to me, climbs on top of me trying to reach air. Meanwhile I could push us back to the wall and swim fine, but my brother is basically dunking me and holding my arms down and drowning me! I don't know how long this goes on at all. It felt like quite a long time. Maybe 1 minute. We're drowning, 3 feet from the wall of a pool. Then the person we were jumping around grabs us and pulls us to the side. The horrible part was the after part, that's what I still don't like thinking about. My little brother crying, my parents talking to me, me crying, feeling so guilty for almost killing my brother. But when ever I'd start to remember that, I'd just be like "yeah that happened and I don't think about it. That and that other thing."

I still don't remember what that other thing is. Isn't that weird? I really chose to mentally block something from my memory and it worked. I don't think it's anything really horrible like abuse or something. But still, what was it?