People look for patterns and explanations. It's a very common trait in humans to do that, though not everybody needs to do so. Perhaps it doesn't matter for you, or to you, whether your childhood experiences play any part in the fact that you have a difficult time socialising. That doesn't mean it doesn't matter for somebody else, though. And maybe it matters less whether the childhood memories are true or not (after all, as my T is fond of saying, all memories are distorted) than whether they have an impact on us today or not.
Secondly, looking at links between childhood events and current state is not the same as casting blame - it's a way of trying to understand, not of pointing a finger at somebody else and saying "It's all your fault".
The same event and environment does affect different people very differently.

I'm very reluctant to tell my T anything about my childhood, but I'm slowly learning to trust that he's the one who has the experience to judge whether something is relevant or not. As far as I'm concerned, that's one of the things I pay T to do. (However, my T has never tried to create that life narrative. So far, at least.)

Also, my current T is the first one who has asked me anything at all about my childhood. So it's all kind of new for me - so maybe my experiences aren't the most representative ones.