For me, it's because I find it very difficult to change the thinking and feeling of 4 decades overnight, from one conversation. My T has had to tell me multiple times that what happened when I was 13 was not my fault or responsibility, but because I was convinced it was for 40 years, it takes more than just a couple of assertions otherwise to change how I feel about it. I know intellectually that he's right, but I still don't feel it 100%. T has told me that he'll say it as many times as it takes for me to truly believe it and that it's perfectly okay for it to take a while.