When I was 11 and alone, I randomly changed channels (we only had the 3) and was faced with a bunch of corpses being shoved into a grave by a caterpillar. I remember that as if it was yesterday, and with everything I learned since then, that was the horrible anchor. But like you probably too, I wouldn't want to unsee it either. And I still sometimes can't help but wonder about the streets I walk through. Did some of those houses see people get dragged out and carried to their murder? How would the dead judge our too common unwillingness to speak out against injustice, even though we're very free to do so in comparison to them? There's so much, but I fear it less than I fear looking away.
While I also think testimonies, big and small, by real people (e.g. https://www.youtube.com/user/YadVashem/videos ) are important and need to be preserved, I can honestly say that for me, they were not really necessary, that is they came long after this had already become and integral part of me. Even "just" what can be read in books sufficed, but that's because I went looking for it, because I needed to learn. Similarly, I think it's perfectly possible for people to be so jaded to even shrug off a testimony given in person. So that's both good and bad news, I guess?