I hope someone can give me some advice on this.

When I was about 10/11 I kissed my brother like they did in movies, I’m assuming I was just curious and experimenting. There was no sexual play just a little bit of kissing. This happened one time and never happened again. My brother is three years younger than me and I feel very guilty about what we did. Me and my brother have a good relationship now which makes me think can he even remember what happened. I feel like some sort of freak for doing this. Do I talk to him about it or shall I just forget?