Is findng out your parents are not perfect. In my case, my mother. I always thought that her leaving me a babysitters all the time so she could be the "woe is me" single parent hero of all women was normal, when in fact leaving your child alone or at a place with no hugs or words of encouragement is neglect. I also didn't know that there was anything wrong with her badmoughing my father to me and telling me that a child only needs one parent. And finally, apparently it is normal to be completely emotionally cut off from the rest of the world from age 3 to age 13 because showing emotion meant that my mother was guilty of not nurturing me enough. And don't get me started on the court system.
Not trying to drawl pity, just having a thought