I think an important factor for some of us can be that we were threatened with death or pain or whatever IF WE TOLD ANYONE. I was anyway. My abuser/ molester took one of my toys and made a motion like he was going to strangle it and said that was what he would do to ME if I spoke about this to anyone. Then, also, when he was done, he would always say "This didn't happen." That made my mind bury it all until I was in my mid-30s when it finally came out one day in therapy, after YEARS of therapy in which we had NO CLUE that it had happened. We just knew that SOMETHING was wrong with me, just had no clue as to what had caused it. I'm in my mid-60s now, so a lot of therapy has gone down since that discovery. None the less, I was so freaked out by the discovery of it, that I quit therapy for many years after its surfacing. I think it took me something like 7-10 years to resume therapy after we discovered it. I just could not face going back to it at all. In fact, when I finally did return to therapy, we did CBT, which addressed present life difficulties, not past traumas. I have never done trauma therapy, other than to have written it all out here in a trauma diary. That was therapeutic, and since I was not "telling" anyone, just writing it out, the feeling of danger never came to me about writing it. I was told not to TELL anyone. Writing was not part of my vocabulary at that age, so thankfully writing it did not at all feel uncomfortable!
