One psychologist told me, "children are powerful triggers." My flashbacks started just after we took our 3-y.o. son to his first-ever "pre-kindergarten." We had never entrusted him to someone else before.
Then too, a psychiatrist told me, "Late thirties, early forties... that's when these things tend to emerge." I was 42 when my mental roof fell in.
Another "tipping point" just before my FB's started was having a serious illness for several months (strep pneumonia). The doctors were asking lots of questions about my childhood health, and I didn't know the answers. Also, my breathing was impaired (well, duh!), which reminded me that the perv tried to suffocate me with a pillow.
IOW, many things can set off recall of CSA and other traumas--even things that don't seem connected in any way. Peace.