I think it's possible.
From what I understand, we all keep all of our memories, but most of them are hidden. Think of it like having some memories in brambles and bushes, and others are like little paths in the woods, can be accessed if there is a trigger or something. Others are like formally maintained hiking paths, still others dirt roads, paved roads, interstates, etc. If the brain accesses a memory often, or the memory is so significant (wonderful or traumatic), the pathway can be burned very clearly. Other memories are never accessed again and are overgrown by the bushes (what you had for lunch on December 19, 2007, for example).
Obviously a circumcision would be traumatic and would qualify as something to burn a memory of, but that issue is complicated by our transition from nonverbal beings to verbal beings. When we make that switch, we use our brains very differently. We verbal beings can't even comprehend what thinking nonverbally is like. So for most of us, things that happened before we were fluently verbal aren't really accessible, partly because they get overgrown by those brambles and partly because it's hard for us to "translate" those memories since they are nonverbal.
So I would think that the vast majority of us do not have the ability to consciously recall events that happened when we were preverbal - even though those memories are still there.
But... it IS possible that a few, very few, people bring it over. I suspect that this is only possible if the person recalled (either consciously or was triggered by something to recall it) the event during their transitional time, when they were maybe 18 months to 3 or 4 years old. If they recalled the event strongly enough during a time that they still could access their nonverbal memories, they would effectively "translate" that memory into a verbal one, and thus be able to visit it again later when their nonverbal memories are lost.
So I could see that maybe a few boys thought about their circumcision when they were little - either they were just very reflective children, perhaps, or maybe they experienced something in their toddlerhood that reminded them. Thus making that memory accessible, especially if they continued to think about it from time to time throughout their childhood and adulthood.