I do agree it is a symptom of Asbergers but do think it can be fairly common in other unhelpful thinking styles and that sometimes relate to previous trauma.
There usually is a huge difference in the extent of the black-and-whiteness and lack of empathy and Theory of Mind between NTs (neurotypicals, i.e. non-autistic) with a trauma history and people with AS.
No, sorry. It is not just idioms. It is down-to-a-t-literal regarding the content expressed and excluding fully the content not expressed. If you want to find out what AS is, as well as the extents of AS vs. PTSD, I'd suggest reading "The Complete Guide to Asperger's Syndrome" by Tony Attwood. Then continue with others.
Just saying. If I were the original poster, I would check it out. In my view, and I have 32 years of experience with AS in my personal and professional life, what is said in the original post exceeds the PTSD extent of b/w-ness and literalness. I am aware though that this is just one post and only the personal view on the matter (subjective) by the original poster.
Also, on a side note, when you have people with AS around you, in your family growing up, friends you choose, colleagues you work with, that way of communicating and all can become your normal. Especially when you don't know what AS is. When something is your normal, you do not really question it too much because "everyone is like that".
Just saying. I will leave this thread now.