I recently described my lack of chattiness to a new friend as "brain taking a long coffee break." Everyone wants to call that "shyness" but that would mean I had words to utter but was afraid to say them.
For decades I did not have the vocabulary to describe this phenomenon. #Allistic brains seem to light up in company; mine shuts down and takes a long smoke break.
I have about an hour of conversation in me per day, tops, on average.